mineral processing production line 7 schedule

production line, mineral processing, concentration of ore - xinhai

Xinhai mineral processing equipment mainly include: grinding equipment, flotation equipment, dewatering equipment, magnetic separation equipment, and so on. Some of the equipment is Xinhai independent research and development, and has been awarded national patent. View details

Gold CIP Production Line adsorbs gold from cyaniding pulp by active carbon including 7 steps: leaching pulp preparation, cyaniding leaching, carbon adsorption, gold loaded carbon desorption, pregnant solution electrodeposit, carbon acid regeneration, leaching pulp. View details

Xinhai has been committed to providing customers with more professional services in the turnkey solutions for mineral processing plant, optimized its services continually, and formed its own set of service system, besides, Xinhai set up Mining Research and Design Institute, ensuring the smooth operation in plant service. The following is the detailed flowchart of Xinhai mineral processing plant services. Xinhai proceed from every detail, creating the comprehensive green and efficient mineral processing plant for all customers.

Xinhai has been committed to providing customers with more professional services in the turnkey solutions for mineral processing plant, optimized its services continually, and formed its own set of service system, besides, Xinhai set up Mining Research and Design Institute, ensuring the smooth operation in plant service. The following is the detailed flowchart of Xinhai mineral processing plant services. Xinhai proceed from every detail, creating the comprehensive green and efficient mineral processing plant for all customers.

Xinhai has been committed to providing customers with more professional services in the turnkey solutions for mineral processing plant, optimized its services continually, and formed its own set of service system, besides, Xinhai set up Mining Research and Design Institute, ensuring the smooth operation in plant service. The following is the detailed flowchart of Xinhai mineral processing plant services. Xinhai proceed from every detail, creating the comprehensive green and efficient mineral processing plant for all customers.

Xinhai has been committed to providing customers with more professional services in the turnkey solutions for mineral processing plant, optimized its services continually, and formed its own set of service system, besides, Xinhai set up Mining Research and Design Institute, ensuring the smooth operation in plant service. The following is the detailed flowchart of Xinhai mineral processing plant services. Xinhai proceed from every detail, creating the comprehensive green and efficient mineral processing plant for all customers.

Engineering consulting can allow customers to have an overall concept of dressing plant, , including mining value, useful mineral elements, available mineral technology, mineral plant scale, equipment required, project duration, making customer know fairly well.

Engineering consulting can allow customers to have an overall concept of dressing plant, , including mining value, useful mineral elements, available mineral technology, mineral plant scale, equipment required, project duration, making customer know fairly well.

graphite powder processing plant | mineral processing equipment supplier | vostosun

Cooperation background In recent years, most countries pay significant attention to the development of environmentally friendly alkaline manganese batteries, and have banned the production of mercury batteries. In cooperation with the powder engineering laboratory of Tsinghua University, Vostosun has achieved great innovation for various spheroidization technology of graphite powder. Vostosun can provide graphite spherical production lines for low mercury/mercury-free battery materials, and the finished products can be used in mobile phones, electric motorcycles, electric vehicles and so on.

Conditions of production line Process material: flaky graphite, microcrystalline graphite, artificial graphite Feeding fineness: 800 mesh (15 mD10), 325 mesh ( 45 mD90) Discharging fineness: d50=13-18 md9025-30 m (stepless adjustable) Spheroidizing rate: 55%-70% (flaky graphite and artificial graphite), 50%-60% (microcrystalline graphite) Tapped density: 0.85 g/cm3 Handling capacity: 400-600 kg/h Working mode: continuous

The production line of the graphite powder processing line can reduce the ratio of product/raw material to 1:1.7, and the line is equipped with laser precision welding rotor and adjustable speed high speed motor, effectively delivering the precise control of graphite by rotor. The working condition is automatically controlled by the system associated with low resistance dust collector, titanium carbide wear resistant rotor disk and hammer head, low noise and low vibration fan.

Add.: 5A.ORIENTAL INTERNATIONAL TECHNOLOGY AND SCIENCE BUILDING,NO.58 XIANGCHENG ROAD,PUDONG DISTRICT,SHANGHAI,China Add.:No.57,Str.Sovetskaya, Lipetsk, Russia Tel.: Mobile: E-mail: [email protected]

mineral processing equipment manufacturer

Yantai Mining Technology & Equipment Inc is focused on providing a whole range of services of Mineral Processing EPC, including process testing, engineer design, products, installation & commissioning, local training and operation management. The teams of geologists, processing & mechanic experts of we are traveling around the world with accumulated experience of 400 EPC projects.

Our EPC provides mine owners with services including beneficiation test, mine design, etc.. Our company is committed to solving the common problems of dressing plant such as budget overspending, schedule delaying, disputes of the manufacturers, unclear responsibility of after-sale service, etc.

mining business plan

The following document outlines a mining business proposal to design and construct a free standing toll plant facility, known in this document as Peru Toll Treatment (PTT), in southern Peru to accommodate the needs of a growing quantity of small scale miners who produce up to 14 percent of the countrys annual gold production. The plan includes the basic design criteria on which the plant will be built, the model for generating revenue and a detailed annual cash flow forecast for the proposed operation for a period of ten years.

The proposed 7.5 tonne per hour plant will cost approximately $2.9 million to design (including $473,000 in VAT taxes which will be reimbursed from revenues), construct and startup and will generate revenues by providing a custom milling facility for small producers who sell their production to the plant. This business opportunity does not include any involvement in mining or the production of mineral. It only involves the purchase and treatment of gold minerals. While the market for such a plant can easily accommodate a 350 tonne per day operation the business plan is based on processing 150 tonnes per day only with the ability to later expand to multiple plants of 350 tonnes per day each.

The plan calls for raising the $2.9 million from public equity financings. Once in operation, the operating company will retain $250,000 for working capital and all subsequent profits will be paid to the shareholders every 3 months as a dividend. The cash flow model is for a single plant of 150 tonnes per day, calculated on an after tax (Peruvian fiscal regime) basis for a 10 year project life. On a project basis using a $1500 per ounce gold price and a discount rate of 10 percent the project will generate a net present value of almost $22.0 million. The payout of the capital investment on a project basis is 1.1 years and the calculated rate of return is over 200%. Testing the project economics against changes in the primary input variables (capital cost, operating cost and gold price) indicates that the project is very robust and even with significant increases in costs or reductions in revenue sources the project has a positive rate of return.

Appendix 5 of this Business Plan includes expressions of interest from two formal miners who are 100% owners of their concessions and can offer 450 tonnes per day of production. PTT has visited one of the mines and confirms the potential for a 350 tonne per day operation. In order to facilitate the commencement of mining production PTT intends to rent $100,000 of mining equipment to these owners as part of a preferred mineral provider position. This cost has been included in the project economics.

This Business Plan is based on the construction and operation of 1 plant to demonstrate the profitability of the toll treatment plant concept. During this first year of operation the management will be evaluating expansion opportunities in other areas of the country as well as at the current site. PTT intends to build and operate 4 350 tonne per day gold plants in Peru within 5 years and the company will generate an estimated after tax, net cash flow of $40 million per annum.

PTT believes that health, environmental and social improvements will accrue to the informal miners in those areas of Peru in which the Company operates and these are important aspects of the expansion phase of the project. Current informal mining practice involves the uncontrolled use of the toxic substances mercury and sodium cyanide to obtain the gold at very low recovery rates. Many of the informal miners are, in effect, stealing the gold from the government or legitimate concession holders causing significant social disruption in the affected areas of the country. It is, therefore, an important aspect of this business plan to reduce the negative health and environmental aspects of informal mining activity by offering an advanced technology which safely removes up to 90% of the gold from the ores resulting in a much higher payback to the people who mine the ore. Purchasing gold ores from informal miners who do not own their concessions is illegal in Peru and rightfully so. It is the intention of PTT to work with informal miners to ensure that they legitimize their activities by entering into registered contracts with the owners of the mineral resources.

There are risks to the project but most can be mitigated by doing appropriate engineering prior to plant design and construction. The plant will use standard gold processing technology and country/political risk is the greatest threat to the project. Peru has signed free trade agreements with both Canada and the United States which is normalizing its business activities.

From the days of the Spanish conquest, foreigners have come in search of theproducts of Perus mines and the mining sector has been a core part of the economy up until the modern era. Operations at the historic zinc-mining center of Cerro de Pasco began in 1905 and the Metallurgical Complex at La Oroya started production in 1922. Much of Perus rail network was created to serve the needs of the mining industry. Nevertheless, relatively little exploration was carried out in the 1960s and 1970s and development of the mining sector came to a halt. Perus favorable geology has been under-exploited and while reserves have been exploited intensively in the US, Canada and Chile, to date only about 12 per cent of Perus mineral resources have been identified.Peril has the capacity to double or triple current levels of output, especially in base metals. In all, Peru holds about 16 per cent of the worlds known mineral reserves, including 15 per cent of copper and 7 per cent of zinc reserves.

Mining activity contributes 45% of foreign currency to the national economy which implies investment commitments, promotion of a modern managerial philosophy, increased responsibility towards safety and care of the environment as well as improved rural social development.

While mining provides relatively few jobs, it is vital to Perus economy in other ways. Thanks both to high mineral prices and rising output, mineral exports were up by almost half last year, and accounted for 55% of total exports. Mining brings in 29% of total tax revenues. Of this money, the government last year returned $138m as a local royalty to mining areas, most of which are otherwise poor and remote.

As a result of its favourable geology and improving economy Peru is taking a dominant position in the production and sale of many base and precious metals. It occupies first place in Latin America in zinc, tin, lead and gold; second place in silver and copper; fifth in iron. In the context of world mining production, Peru is in fifth place in gold, second place in silver, third place in tin, fourth place in zinc and lead, fifth place in copper and twenty-fifth place in iron as shown on Table 1 below.

Since the constitutional and business/economic reforms of the early 1990s Peru has enjoyed a robust economy with strong economic growth tied closely to the business cycles of its primary metals production. The country allows any person or company to create and own a Peruvian entity and all profits can be repatriated to another jurisdiction free of additional levies.

The tax code is relatively simple and taxes are calculated as 30% of net profits after depreciation. Machinery and equipment are all subject to depreciation on a straight line basis and the majority of items are considered to have a 10 year life. A recently introduced royalty provision requires an additional payment to the government depending upon mine production level the higher the production level, the higher the royalty to a maximum of 3% of sales. Currently small producers (less than 350 tonnes per day) are exempt from this royalty.

Labour laws are not restrictive and employee burden is approximately 30% of base salary. Unskilled labour is relatively inexpensive and university trained and skilled trades labour are paid commensurate with the level of training. Skilled and professional talent exists in abundance and is of a high quality.

Peru has a long history of political instability. In 1993 Alberto Fujimori enacted several far-reaching legal and constitutional reforms which have stabilized the political situation. Although he left the country under a cloud of suspicion in 2001, his legacy is a well performing economy and a gradually improving jurisprudence and governing infrastructure. As the government bureaucracy becomes more stable and professional the incidence of corruption is diminishing. Corruption remains an unfortunate fact of life in Peru but it has noticeably declined in the past 10 years.

The governments of Alejandro Toledo and Alan Garcia have been much maligned but the outgoing president has turned over to the new president (on July 28, 2011) an enviable economic record and a strong financial position.

There is a confidence in the Peruvian economy as it moves forward buoyed by continued high commodity prices and a wider spreading wealth across all social classes. Many of functionaries have made considerable personal advances on thebasis of the resurging mining economy so it is expected that the new government will be friendly to the mining industry and investment.

A significant benefit of this business plan, apart from the very robust economics, is the opportunity to advance the indigenous mining industry through improving the health and environmental impacts as well as obtaining a higher recovery of gold from the mined rock returning a greater economic benefit to the mineral owners the people of Peru. PTT has commitment letters for 450 tonnes per day of mineral production from two legitimate, small scale miners and as it expands production beyond this, its policies will have beneficial impacts as follows;

Informal and small miners in Peru currently do not have the financial capacity to install modern, large capacity plants. As a result, the mine producers crush the ore in stone grinding mills called quimbaletes and then agglomerate the gold in the crushed material with natural mercury. Not only is the process very labour intensive with low productivity, it also leads to significant health problems. In order to release the gold from the mercury amalgam, the material is heated on open fires to boil off the mercury creating a mercury poisoning risk for anyone nearby including children. The mercury vapour eventually cools and condenses on the ground to create an ongoing health hazard.

As described above the uncontrolled use of mercury and sodium cyanide often lead to issues of significant environmental degradation. The gold mining regions of Peru are noted for the deep blue staining in areas where ore is leached in cyanide baths that are developed without due regard for the environment. The baths are rarely lined with geomembrane to prevent the liquid toxins from moving out into the rock and eventually into the nearby water courses. To argue that many of these areas are in arid zones with no natural vegetation or water courses does not obviate the fact that environmental destruction occurs when toxic materials are allowed to accumulate in surface soils.

All subsurface materials are owned by the people of Peru under the trusteeship of the Peruvian government and any practices which do not optimize the recovery of wealth from these subsurface materials denies thepeople of Peru their rightful share of this wealth. The antiquated processing methods described above rarely recover more than 35% to 40% of the gold from the ore material. Modern plant recovery techniques can often recover more than 90% of this same gold returning a higher value to the people of Peru.

The current state of informal mining in Peru is somewhat chaotic and in many cases, informals are, in effect, stealing ore from the concession owners who are powerless to stop them. PTT will not purchase ore from informal miners who do not have a rightful claim to the ore they are selling and will go further in attempting to bring some order to the regions in which it works by;

Thus PTT will permit informal and small scale miners to earn much greater returns on their labour (through higher recoveries of gold) with much less effort. Modern plants, built to the exacting environmental standards of the Peruvian Ministry of Energy and Mines using state of the art gold processing technologies will result in an improved environment and fewer health risks to the miners. Perhaps as important, the social chaos which characterizes many gold mining areas of Peru will become more orderly as concession owners are paid a return (royalty) on the gold mined from their concessions.

The Nazca-Ocona Gold Belt is 350 km long and 40 km wide covering portions of three Departments; Ayacucho, Ica and Arequipa. It is typified by narrow, gold bearing quartz veins, which are formed in hypothermal to mesothermal environments. The mineralized structures are found in andesitic volcanic rocks and in the intrusives of the Andean Batholith. Veins found to crosscut granodiorite and diorite, tonalite or andesite often contain higher gold grades in the diorite, tonalite or andesite than in granodiorite. The mineralization is known locally as rosario formations due to the fact that the veins tend to narrow and widen in a regular pattern much like the beads on a rosary.

The mining activity that has developed in the Nasca-Ocona belt has largely been by artesanal methods although there are some more modern mines in the area. There exist also mining formal activities of iron and copper.

Artesanal mining is characterized by its labor intensity and lack of modern mining equipment. As a result, the miners develop lodes or veins of narrow thickness but high grade Au. The veins range in width from 30 centimeters to 1.5 meters. In some exceptional circumstances they reach up to 2 m wide. The concentrations of Au range from 15 to 150 grams per tonne (gpt).

The artesanal miners selectively extract from the lode and veins using a technique called the circado. This is essentially a resuing method whereby an opening large enough for a person to work is made alongside the vein and the ore is then slashed off the wall. This reduces dilution and the ore is removed from the opening in small canister with as much as 1.6 grams of gold per 45 kilogram canister (35 grams per tonne). The treatment of the mineral begins with the pallaqueo, or hand sorting to selectively upgrade the ore before being processed or sold.

The mineral extracted from high grade (> 2 grams gold (Au) / canister), is crushed and processed directly in a quimbaletes or manually operated, wetted grinding stones at a rhythm of 30 minutes per canister. While no formal reporting is done it is believed that the gold production in lca and Arequipa is 9 tonnes of dore annually.

Cyanide is sometimes used to extract the gold and the dissolved gold is recovered using activated charcoal. Typically the tails of the quimbaletes process contains important quantities of gold that can be recovered only by cyanide. The grade of the tailings ranges between 12.8 and 25.6 gpt and contains considerable quantities of mercury (introduced from mercury amalgam processes) which end up in the cyanidation tails.

The map shown above comes from information taken from the Ministry of Energy and Mines (MEM) and includes 68 artesanal mining locations. The MEM database includes a total of 270 locations and even this is known to understate the actual number of small mining operations.

It is believed that less than one third of the mines are registered, or included in the reports of MEM. Therefore, the total material that is mined and treated is unknown. It is known, however, that the amount of informal mining activity has increased with the increasing gold price. This increases the mining potential of the zone.

Small mining in Peru is divided by MEM into two categories: traditional and artesanal. Not only is artesanal mining labour intensive with only rudimentary equipment, it is, also in general, an informal activity. Traditional mining makes use of mechanical technologies and is formally registered with the government following norms of labor relations, safety and mining hygiene, environmental requirements, the payment of taxes and reporting to the MEM. According to the statistics of the MEM, the artesanal mining contributes 14 % of the entire gold production of Peru. Half of the national exports come from the mining and from 1998 the gold is the principal product of national exportation.

The geography of Peru is such that the coastal plain is entirely desert except in those areas in which rivers run westward out of the Andean highlands. The entire coast then is truncated every 100 kilometers or so by irrigated arid lands stretching a kilometer or two on either side of the river. The mining activities which are of interest to this report take place within the mountain barrier and usually at elevations below 3500 meters above sea level (masl). While the straight line distances from these mines to the coast are not large (less than 100 km) the steep nature of the terrain makes transportation of the mineral quite difficult and expensive.

This business plan proposes to locate the plant approximately 30 kilometers south of the city of Nazca at a distance of 500 meters along the PanAmerican Highway. The next step in development will be to apply for additional mining leases, purchase the mineral and surface rights to the plant site location and convert the lease underlying the plant to a beneficiation plant lease.

Infrastructure for the plant is excellent with water available from either a well on-site (50 meters) or via pipeline approximately 5 kilometers away. Construction to bring electrical power to within 2 kilometers of the site is underway and is currently 7 kilometers from the plant location.

A local metallurgical laboratory has completed 3 cyanidation tests to determine the optimum dosage of cyanide to recover the gold in ore from the Nazca-Ocona gold belt. The composite ore sample used had a head grade of 19 grams per tonne and the ore was leached for 48 hours with intermediate samples taken to determine the rate of gold dissolution. The results of this work are shown on Figure 4 below.

It is important to note that PTT intends to use the latest gold processing technology to ensure that all Peruvian regulatory requirements are met or exceeded. None of the technology to be used is experimental and all of the equipment required can be readily manufactured in a number of fabrication shops in Peru.

This test work forms the basis for the operating cost estimate and a preliminary flowsheet as discussed below. Based on other plant experience with this material and the preliminary bench scale testing that was done it was determined that a simple cyanidation plant would recover between 92 and 95 percent of the gold from the ore.

PTT obtained a 50 kilogram sample of ores from the Nazca-Ocona area and retained the private laboratory of TECSUP to undertake 3 cyanidation leach tests at different cyanide dosages. The report from this laboratory work is included in Appendix 1 to this document.

The grade of the 50 kilogram sample was 18.7 gpt of gold and the sample was pulverized to an 80 percent passing 200 mesh size consist for the testing. The three cyanide dosages used 0.5, 1.0 and 2.0 grams per liter and the consumption of cyanide after 48 hours was 3.06, 3.58 and 3.61 kilograms per tonne. If the material is leached for only 24 hours the recovery is essentially complete and the

consumption of sodium cyanide drops to 2.5 kilograms per tonne. The three samples were placed in a glass container and agitated for 48 hours. Twenty milliliter samples of the liquid phase were extracted periodically as shown to determine the rate of extraction and identify the optimal concentration of sodium cyanide. The results of the analysis are shown on the graph in Figure 4 below.

The standard process for this plant is shown on the preliminary flowsheet on Figure 5. The list of equipment is shown on Table 3. Ore will be brought by the miners to the plant in small trucks with an average size of 10 tonne lots and the material will be dumped on a compacted patio in a segregated bay. The material will be sampled and analyzed for gold grade, impurities and moisture allowing a fair assessment to be made of its value. The owner of the material will be paid on the basis of the analytical results. The method of payment is discussed below.

From the patio, the ore will be fed by small loader over a scalping grizzly and into a 60 tonne feed bin which discharges onto a screen. The screen oversize passes into a jaw crusher and the undersize passes by conveyor to a second screen. The discharge from the jaw crusher passes onto the same conveyor and also across the second screen. The oversize from the second screen goes to a cone crusher and the undersize passes by conveyor to a 150 tonne fine ore bin. Based on the granulometry of the material tested, less than 25 percent of the ore will need to be crushed.

The fine ore is taken from the bin via conveyor and discharged into a 7 foot by 7 foot ball mill. Water, lime and cyanide are added at this point. The ball mill discharge is pumped to a hydrocyclone with the underflow going back to the ball mill and the overflow feeding a 5 foot by 5 foot ball mill. The discharge from this ball mill is also sent to a hydrocyclone with the underflow going back to the ball mill and the overflow going to the first of four, agitated leach tanks.

The leach tanks work in series and by the time the solids pass through the fourth tank the gold has been leached from the fine solids. The slurry then passes into the first of three carbon-in-pulp tanks where fine carbon particles move in counter current with the slurry to absorb the gold laden cyanide solution. The slurry is pumped from the bottom of the third tank and sent to a standard tailings facility and the liquid phase is sent to the first of three desorption tanks.

The gold laden carbon is washed with stripping solution to remove the gold from the carbon and this solution is then sent to a small electrolytic cell where the gold particles are plated onto a gold cathode. The cathodes are periodically taken to a furnace and melted to make ingots of dore bullion. The carbon is washed with hydrochloric acid to regenerate its adsorption qualities and then sent to a rotary kiln to be reactivated and reused in the process. The sintered carbon is passed across a double deck screen to remove fine particles generated in the process. The fine

carbon which is removed will be stored for subsequent burning to capture any residual gold particles. The first step in the project process following financing will be to do more extensive metallurgical testing to finalize the process flowsheet and estimate an accurate mass balance. It is anticipated that several cost savings will be made at this point. For example the gold ore from the Nazca area is very highlyoxidized and is delivered to the area plants with few rocks larger than 6 inches in size. It is not considered likely that much crushing will be required. Also the sizing of the ball mills will be more accurate and it is likely that smaller equipment will be used. The rapid reaction kinetics may allow for fewer tanks to be used. It is considered that the flowsheet presented in this business plan is conservative. The detailed design to be done post-financing will result in a target cost estimate and construction drawings.

The net result is a capital estimate accurate to within plus or minus 15 percent. Added to the installed equipment capital cost will be working capital to maintain an owners team during design and construction and to pre-purchase a one week supply of ore. The capital cost estimate quotation is included in Appendix 2 to this Business Plan.

Discussions have been held with a reputable Peruvian engineering company with extensive experience in building this size and type of plant. Basic contract terms have been agreed upon pending financing. Their preliminary cost estimate to build the plant on a turnkey basis was less than this constructors estimate.

Security is an issue whenever there exists a small object of high value such as a brick of dore bullion. Security will be built into the plant design by surrounding the facility with a fence or wall and putting the final processing equipment into securedbuilding. Workers will be required to wear company clothing and change and shower on site. Special traps will be built into all effluent discharges and private security will protect the plant.

The removal of gold bricks will be done under contract with one of the international, bonded security companies that operate in Peru and they will take custody of the gold at the plant site. There is a small asphalt airstrip at Nazca and flying the gold from this nearby town will be investigated. Plant security will be fully addressed in the detailed design stage following financing.

The plant operating cost estimate is developed from the power cost and reagent costs which are the largest cost items. Power requirement is determined by the horsepower requirements of the plant equipment and it is assumed that all power will be from the national power grid at a cost of US$0.10 per kwhr. A backup generator will be available in the event of power outages which are frequent in this part of the country. The plant operating cost estimate is shown on Table 5 below;

This manpower schedule assumes two, 12 hour shifts per day for 365 days per year requiring 3 shifts of personnel. The plant availability is assumed to be 95 percent resulting in 346 effective operating days per year. The labour cost shown in the operating cost estimate is based on this labour schedule assuming that qualified labour is paid $600 per month and tradespeople are paid $630 per month. The payroll burden is assumed to be 30 percent additional to the payment of 15 salaries in every 12 month period. Additionally a 6 percent profit sharing bonus is paid. The manpower complement at the plant is 21 operators, 8 technician/tradesmen, 3 shift supervisors, the plant metallurgist and the Operations Manager.

The Peruvian fiscal regime is well understood and has been in place for the past 12 years. The recent election assures another 5 years of political peace and the ruling Aprista party is pro-mining and is not considering significant changes to this tax regime. It is emphasized that PTT will follow all Peruvian laws with respect to the paying of all tributes and taxes including payroll taxes and profit sharing and this is reflected in the cash flow model used in this Business Plan.

Income taxes are a flat 30 percent of resource revenue and most capital expenses are amortized straight line over a 10 year useful life. The lack of accelerated write-offs has been a topic of conversation between the mining industry and the government for some time but with commodity prices at high levels it is not considered likely that any changes will be instituted at this time.

The development schedule is shown on Figure 6 below. When the project has been financed there will be a one month design phase to confirm that the flowsheet is appropriate for the project. Fifty kilograms of ore will be obtained from the operations which have signed letters of intent for this purpose.

Discussions have already taken place with a local engineering company which has the competency for this project and they have expressed, in writing, their interest in providing a lump sum bid to engineer, purchase and construct the plant. Engineering of the plant will commence as soon as the design of the flowsheet is known in sufficient detail to start sizing the equipment. As previously stated, as much as possible, the plant will be built in modules which can be easily transported to the site and quickly interconnected. Plant engineering and purchasing is anticipated to take only 2 months as many of the contractors already have construction drawings for the equipment to be installed.

As soon as the equipment list is ready, orders will be placed for the components which will all be available locally. As each plant module is designed fabrication will commence. It is anticipated that construction of the plant will require 4 months.

All necessary permits will be applied for immediately following financing. These will include construction permits, water licenses and operating permits. A local consultant with specialized skills will be hired to write the necessary permitting documents and that the whole process will take from 3 to 5 months.

The cash flow results are shown in Appendix 4 to this report and summarize the costs and revenues for a 10 year project life. The table shown assumes a gold price of US$1500 per ounce and a gradually increasing gold feed grade.

The revenue formula for the plant is based on two items; 1. A plant charge per tonne of throughput based on gold price. 2. A recovered gold payable equal to 90% of the total plant recovery. The company retains any gold recovery above 90%. 3. A marketing fee of US$20 per tonne.

When the gold ore is brought to the plant it will be evaluated and a purchase price assessed based on the average gold price of the previous 7 trading days, the ore grade and moisture content and the plant revenue factors identified above.

The processing charge was calculated from an understanding of the process charges for the major competitor to PTT. While not wanting to upset the current pricing regime, PTT will be at or below the competition at any given gold price. Note that this calculation is based on pricing at a time when the gold price was $450 per ounce. It has moved up since this time and the economics presented are based on an increase of $20 in the process charges shown below. The deviation from our competition widens as the gold price increases as shown in Figure 7 below. For clarity, this figure shows the amount paid to the sellers of the ore and is not the amount paid to the plant.

The processing fee floor value was determined from a supply cost analysis at a gold price of US$300 per ounce and a grade of 10 grams per tonne. It was determined that a charge of US$54 per tonne of ore is required to obtain a 25% rate of return on the project (at a gold price of US$300 per ounce). Based on this analysis, the processing charge is calculated according the following formula;

The operating cost has been described above and the cash flow analysis uses this cost with an additional 4% for marketing and head office administration. As gold prices have topped $1500 per ounce and additional $20 per tonne was added to this processing charge.

Two written expressions of interest have been received from concession owners who have mines currently not operating. PTT have visited the Erika mine and confirm that it is capable of producing 350 tonnes per day of gold mineralization. The total production being offered by the two formal mining companies is 450 tonnes per day.

Taxes and royalties are as described above. The capital cost allowance for all capital requirements is assumed to be a 10 percent, straight line deduction for 10 years (the assumed life of this project).

The net cash flows are then calculated as shown in the Appendix and, for this base case production scenario, the project net present value at a 10 percent discount rate is $22,000,000, the rate of return is over 200% and the payback period is 1.1 years. Figure 8 indicates the expected net present values at varying discount rates for the base case cost and revenue assumptions.

A sensitivity analysis for the project has been undertaken as shown on the spider diagram in Figure 9. The input values of gold price, operating cost and capital cost have been varied in 25% increments from 25% of base case to 175% of base case values. The slope of the criterion lines indicates how sensitive the project economics are to changes in these criterion the steeper the line the more sensitive the project economics are to that variable.

It can be seen from this sensitivity analysis that the project is extremely robust and is largely indifferent to capital cost nor very sensitive to gold price as most of the plant revenue comes from the processing charge.

The technology for winning gold from these types of ores is well understood and there are other much older and quite dilapidated plants operating successfully in the area. It can be seen from the economic sensitivity analysis that the project remains economic even with significant changes in capital and operating costs. When capital and operating costs are at 175% of the base case ($4,200,000 and $58.00 per tonne) and the ore grade and gold price are at 50% of the base case values (10 grams per tonne and $325 per ounce) the project will have an NPV10 of $3,682,000.

As stated previously, 14% of all the reported gold produced in Peru comes from small scale and informal miners. With high gold prices there are literally thousands of small miners operating in the area of interest and there is not enough plant capacity for them. Currently, a miners cooperative is being created to subsequently sign an agreement with the writers of this Business Plan.

The plant will not compete on the basis of pricing but rather on the honesty of its operation. The small miners will be given full value for their ore as determined by a third party, internationally recognized laboratory which is not currently the case. As well the plant site is located within 1 kilometer of the main Peruvian highway while the competitors plant is located approximately 2 hours from the highway along a difficult, narrow gravel road. The plant location will guarantee a continuous supply of feed stock.

Plant management has been chosen with great care and special attention will be taken to hire only qualified and reputable people. The company will also contract the services of a reputable firm to periodically audit the operations for shrinkage.

The new regime in Peru has announced that it is committed to maintaining a pro-mining position while directing additional social development funds to the outlying regions of the country. Recently the government announced that informal miners must follow the same environmental guidelines of formalized mining companies. The best insurance against fall-out from such political instability is to maintain a very lowbusiness and community profile. This area of Peru is also known for being relatively peaceful and stable thanks to the self-organizing activities of the informal miners. While they do not operate under the aegis of Peruvian mining codes and laws they do an excellent job of protecting their own interests. The World Bank has specific programs to reduce the use of mercury in artesanal gold operations and will be supportive of this plant.

The signing of free trade agreements with Canada and the United States will do a great deal to normalize Peruvian business conditions in order that they are aligned with North American practices thus stabilizing the business climate.

mineral processing - an overview | sciencedirect topics

Mineral processing, mineral beneficiation, or upgradation involves handling three primary types of ROM material, which have been blasted, fragmented, and brought out from an insitu position. These materials can be used directly or by simple or complex processing and even by applying extractive metallurgy like hydrometallurgical or pyrometallurgical methods. The categories are:

The journey from ROM ore to concentrate and finallymetal travels through many operations of liberation, separation, concentration, and extraction before it reaches the end users. These activities have been diagrammatically summarized in Figs.13.53 and 13.54. Apanoramic view of State of the Art zinc and lead smelting is depicted in Fig. 13.55.

Figure13.54. A complete flow diagram, including crushing, grinding, density media separation, froth flotation, and pyrometallurgical and hydrometallurgical process route to achieve the highest purity of metals. PGE, platinum-group elements.

Figure13.55. Panoramic view of hydro-metallurgical smelter of Hindustan Zinc Limited at Rajpura-Dariba, Rajasthan, India. The smelter has an annual production capacity of 210,000 t zinc and 100,000 t lead metal, and 160 MW captive power plant.

Mineral processing or mineral beneficiation or upgradation involves handling of three primary types of ROM ore material which has been blasted, fragmented and brought out from in situ position. These materials can be used directly or by simple or complex processing and even applying extractive metallurgy like hydrometallurgical or pyrometallurgical methods. The categories are as follows:

The journey from ROM ore to concentrate and ultimately to metal has been conceptualized. The various unit operations used for liberation, separation, concentration and extraction have been discussed in the previous pages of this chapter. The activities and the typical sequence of operations in the process plant have been diagrammatically summarized in Fig. 12.54.

Mining and mineral processing industries have been the key focus of research in many countries due to its increasing sustainability concerns that affect global warming and climate change. This chapter analysed and summarised the significant research outputs published on the environmental impact assessment of mining and mineral processing industries through life cycle assessment (LCA). This chapter presents valuable insights in identifying the gaps, where should the focus be in the mining and mineral processing industries for a sustainable future.

The review results reveal the assessment indicators in human health and ecosystems are key factors that are mostly missing in the previous studies which are crucial for people or community living nearby mining area. This chapter identifies the research gaps to the existing literature that can form the base for future research direction in the field of LCA and sustainable energy integration in mining and mineral processing industries.

Mineral processing operations involve a number of process variables that change randomly with uncertain frequencies. The control strategies developed with the use of PID controllers have been found to be inadequate especially in non-linear systems and systems with large lag times. The present development to solve these problems fall under two categories:

The self tuning control algorithm has been developed and applied on crusher circuits and flotation circuits [22-24] where PID controllers seem to be less effective due to immeasurable change in parameters like the hardness of the ore and wear in crusher linings. STC is applicable to non-linear time varying systems. It however permits the inclusion of feed forward compensation when a disturbance can be measured at different times. The STC control system is therefore attractive. The basis of the system is:

The disadvantage of the set up is that it is not very stable and therefore in the control model a balance has to be selected between stability and performance. A control law is adopted. It includes a cost function CF, and penalty on control action. The control law has been defined as:

A block diagram showing the self tuning set-up is illustrated in Fig. 18.27. The disadvantage of STC controllers is that they are less stable and therefore in its application a balance has to be derived between stability and performance.

The empirical model predicts the process output for a certain predicted time. The error is not fixed as in a PID system, but extends over a time period and minimized. The concept is therefore time based and known as an extended horizontal control system. The algorithm is known as Multivariable, Optimal Control Action or MOCCA [25]. The MOCCA system can be considered as an improvement on the level concept described earlier. It is based on the fact that the prediction of output equals the sum of the future actions plus past control action. It is developed around a step response under steady state conditions by combining:

To derive the model, Sripada and Fisher [25] considered a steady state condition. Also for a single input-single output system (SISO), the predicted output for horizon 1 to P is obtained in N number of step responses. The future and past control actions were written as:

The predicted horizon P, is the number of predicted outputs that the control objective has been optimized The control horizon H is the number of future control actions which minimize the cost function against the predicted horizon.

Optimization of the control system is achieved from performance criteria including any constraints. It is necessary to know the set point and predicted output trajectories for future control effort. The errors and control efforts have to be minimized. For the error trajectory the square of the difference of set point trajectory and the predicted output trajectory is taken. Taking these into consideration Vien et al [6] describes the cost function, Cf, in terms of minimizing the error trajectory plus control effort. Taking the weighted least square performance, the cost function Cf is given as:

Based on the process model, the control block calculates the predictions for future control actions, the supervisory block generates the desired set point trajectory. The feedback loop with filter and disturbance predictor corrects incongruity between the model and unaccounted, therefore unmeasured, disturbances. It also reduces the noise levels. The predictor in the feed back control loop intimates the future effects of disturbances. Combination of the feed back corrections and the predictions from the model provide the necessary estimate of output.

MOCCA has been found to be far superior to the conventional PID or PI controllers and is being increasingly used. It is particularly useful where long time delays are involved. Its advantage is that it uses discrete step response data and can be used to model processes with unusual dynamic behaviour. Its added advantage over the PID system of control is that it rises faster and has no overshoot. This system has been used successfully in control of grinding circuits.

Mining and mineral processing generates large volumes of waste, including waste rock, mill tailings, and mineral refinery wastes. The oxidation of sulfide minerals in the materials can result in the release of acidic water containing high concentrations of dissolved metals. Recent studies have determined the mechanisms of abiotic sulfide-mineral oxidation. Within mine wastes, the oxidation of sulfide minerals is catalyzed by microorganisms. Molecular tools have been developed and applied to determine the activity and role of these organisms in sulfide-mineral-bearing systems. Novel tools have been developed for assessing the toxicity of mine-waste effluent. Dissolved constituents released by sulfide oxidation may be attenuated through the precipitation of secondary minerals, including metal sulfate, oxyhydroxide, and basic sulfate minerals. Geochemical models have been developed to provide improved predictions of the magnitude and duration of environmental concerns. Novel techniques have been developed to prevent and remediate environmental problems associated with these materials.

In any mineral processing operation, the term benefits of scale is used to denote the significant economic advantages can be obtained by having larger production volumes and using larger ships. Larger tonnage operations operate with fewer man-hours per ton, while capital costs for larger machines are less than the multiples of their relative production capacities. In order to compete on world markets, category 1 producers must consider the benefits of scale. For example, in the kaolin industry during the 1970s, a 100,000 tons/year operation was considered to be a reasonable commercial operation. For the current developments in Brazil, a minimum plant size of 300,000 tons per year is being quoted.

For category 2, the annual tonnage requirement is governed by market size rather than benefits of scale. Annual productions from such processing operations typically fall between 10,000 and 100,000 tons per year. The sizes of category 3 operations are typically governed by other factors such as market size or accessible market share.

Mining and mineral-processing industries producing lithium minerals, metals, and salts contribute to the lithium burden in the environment. The processing of lithium-containing minerals such as spodumene, in general, comprises crushing, wet grinding in a ball mill, sizing, gravity concentration, and flotation using a fatty acid (oleic acid) as the collector. The major lithium mineral in lithium ore is spodumene, which is considered insoluble in water and dilute acids. However, a small amount of dissolution may occur during processing of the ore especially in the grinding and flotation stages where some dilute (0.01M) sulfuric acid is used (see Table 6). Tailings are discharged to storage areas, and the decanted water is usually recovered for reuse. Lithium concentrations in tailing dams increase gradually. The dissolved lithium found in the tailing dams of lithium mineral beneficiation plants could be as high as 15mgl1. The repeated use of tailing waters without any treatment further increases the dissolved lithium levels in these waters.

Some of the lithium minerals are more soluble than the others. Manufacturing of lithium chemicals could contribute to the lithium burden in the environment. Most of the lithium chemicals are often more soluble than lithium minerals, and therefore, the risk to the environment could be higher than the risk introduced by the lithium minerals (see Table 5).

Mining and mineral processing can cause arsenic contamination of the atmosphere (in the form of airborne dust), sediment, soil, and water. The contamination can be long-lasting and remain in the environment long after the activities have ceased (Camm et al., 2003). Recent estimates suggest that there are approximately 11 million tonnes of arsenic associated with copper and lead reserves globally (USGS, 2005). In developing mines containing significant amounts of arsenic, careful consideration is now given to treatment of wastes and effluents to ensure compliance with legislation on permitted levels of arsenic that can be emitted to the environment. Such legislation is becoming increasingly stringent. Arsenic contamination from former mining activities has been identified in many areas of the world including the United States (Plumlee et al., 1999; Welch et al., 1999, 1988, 2000), Canada, Thailand, Korea, Ghana, Greece, Austria, Poland, and the United Kingdom (Smedley and Kinniburgh, 2002). Groundwater in some of these areas has been found with arsenic concentrations as high as 48000gl1. Elevated arsenic concentrations have been reported in soils of various mining regions around the world (Kreidie et al., 2011). Some mining areas have AMD with such low pH values that the iron released by oxidation of the iron sulfide minerals remains in solution and therefore does not scavenge arsenic. Well-documented cases of arsenic contamination in the United States include the Fairbanks gold-mining district of Alaska (Welch et al., 1988; Wilson and Hawkins, 1978), the Coeur d'Alene PbZnAg mining area of Idaho (Mok and Wai, 1990), the Leviathan Mine (S), California (Webster et al., 1994), Mother Lode (Au), California (Savage et al., 2000), Summitville (Au), Colorado (Pendleton et al., 1995), Kelly Creek Valley (Au), Nevada (Grimes et al., 1995), Clark Fork river (Cu), Montana (Welch et al., 2000), Lake Oahe (Au), South Dakota (Ficklin and Callender, 1989), and Richmond Mine (Fe, Ag, Au, Cu, Zn), Iron Mountain, California (Nordstrom et al., 2000).

Phytotoxic effects attributed to high concentrations of arsenic have also been reported around the Mina Turmalina copper mine in the Andes, northeast of Chiclayo, Peru (Bech et al., 1997). The main ore minerals involved are chalcopyrite, arsenopyrite, and pyrite. Arsenic-contaminated groundwater in the Zimapan Valley, Mexico, has also been attributed to interaction with AgPbZn, carbonate-hosted mineralization (Armienta et al., 1997). Arsenopyrite, scorodite, and tennantite were identified as probable source minerals in this area. Increased concentrations of arsenic have been found as a result of arsenopyrite occurring naturally in CambroOrdovician lode gold deposits in Nova Scotia, Canada. Tailings and stream sediment samples show high concentrations of arsenic (39ppm), and dissolved arsenic concentrations in surface waters and tailing pore waters indicate that the tailings continue to release significant quantities of arsenic. Biological sampling demonstrated that both arsenic and mercury have bioaccumulated to various degrees in terrestrial and marine biota, including eels, clams, and mussels (Parsons et al., 2006).

Data for 34 mining localities of different metallogenic types in different climatic settings were reviewed by Williams (2001). He proposed that arsenopyrite is the principal source of arsenic released in such environments and concluded that in situ oxidation generally resulted in the formation of poorly soluble scorodite, which limited the mobility and ecotoxicity of arsenic. The Ron Phibun tin-mining district of Thailand is an exception (Williams et al., 1996). In this area, arsenopyrite oxidation products were suggested to have formed in the alluvial placer gravels during the mining phase. Following cessation of mining activity and pumping, groundwater rebound caused dissolution of the oxidation products. The role of scorodite in the immobilization of arsenic from mine workings has been questioned by Roussel et al. (2000), who point out that the solubility of this mineral exceeds drinking water standards irrespective of pH.

A wide variety of minerals processing routes are used for REE deposits (Jordens et al., 2013; Krishnamurthy and Gupta, 2015). For many REE ores, processing techniques for the minerals are unproven on a commercial scale and processing is a major challenge that needs to be considered early in exploration. Physical concentration using density, magnetic and electrostatic properties are normally the most cost-effective. Monazite and xenotime, if reasonably well liberated and coarse-grained, are amenable to physical separation from mineral sands and some carbonatite ores. Finer grained phosphates, and most fluorcarbonates, require more complex and expensive processing via flotation, and/or acid leaching. Eudialyte can be concentrated by physical beneficiation but is difficult to dissolve, although techniques to solve this problem are now available at laboratory and pilot scale.