wet ball mills for garnet powder

anr (wet grinding) | hosokawa alpine

Open-design vertical agitated media mill for single-pass mode Suitable for superfine calcium carbonate and other mineral powder slurries Suitable for continuous operation Low-maintenance machine Ceramic wear protection ensures high degree of whiteness Cost-effective due to low grinding energy requirement

The ANR is designed for the cost-efficient ultrafine grinding of highly concentrated limestone slurries. The operating mode and the design permit the production of extremely high qualities with regard to fineness, degree of whiteness and abrasiveness. The mill design ensures low-maintenance continuous system operation with no expensive downtime periods. The flow pattern through the vertically configured ANR is from bottom to top, whereby the feed material is ground to the required end fineness with the aid of ceramic grinding beads (zirconium silicate or zirconium oxide).

The grinding beads are separated from the discharging suspension by means of a low-maintenance combination of mechanical and dynamic separating element at the mill head. The low-speed agitator ensures an exceedingly low-energy grinding process at low wear rates and high mill service life. The agitator elements and the grinding chamber wall are made of wear-resistant hardened materials. An efficient cooling of the mill stator removes the heat generated during grinding. The geometry of the mill permits trouble-free scale-up to high production-scale capacities. The product line includes small pilot machines of 45 kW as well as production-scale mills up to the MW range.

ball mills & agitated media mills | hosokawa alpine

The classic ball mill Super Orion S.O.is suitable for dry hard crushing and achieves finenesses of under 10 m.For superfine dry grinding: The energy-efficient Pulvis combines a vertical agitator bead mill with a high-performance classifier and is also suitable for grinding hard materials. It achieves a fineness of up to d97 = 1 m. The ATRis characterised by a compact design and high power density. It can achieve a fineness of up to approx. 80% < 2 m.For wet grinding: The robust ANR is suitable for wet grinding of the finest calcium carbonate and other mineral flour slurries.

Ball mills have been used to produce high-quality mineral flours for many years. They are suitable for grinding medium-hard to extremely hard, brittle and fibrous materials. Specific applications include industrial minerals, metal oxides, glass, graphite, limestone, quartz, zircon sand, talc, ceramic paints, inorganic pigments, titanium dioxide, etc.

Ball mills and agitated media mills work according to a simple principle. The balls are freely movable grinding media in a vertical or horizontal drum. The drive sets this drum, and therefore also the balls, in motion. The material to be ground is then crushed between the balls by impact and shear forces. The fineness achieved is also determined by the size of the balls: The smaller the balls, the finer a product can be ground.

The agitated media mill is a special form of ball mill, in which an agitator with stirring elements or an agitator body sets the balls in motion. Hosokawa Alpine offers a range of agitator bead mills for wet or dry grinding.

An important point when using ball mills is the speed. The speed must not be too low, otherwise the balls will just roll off the product will not be ground. Excessive speeds do not have the desired result either, as centrifugal force would then hold the balls against the drum wall, also preventing the product being ground.

Our test center can perform product trials with your test material. This enables you to find the right speed range and the optimal solution for your requirements, including the required fineness. Test which of our ball mills and agitated media mills are best suited to your needs.

Do you want to relieve bottlenecks in production? Do you need grinding support at short notice? Or perhaps buying a new ball mill is out of the question for you for financial reasons? Then we have two alternatives for you: On the one hand, rental machines can be a practical solution for you. On the other hand, we also stock a range of used machines. They are refurbished with original parts and can be adapted to your individual requirements. Get in touch with us!

wet milling synthesis of nh4copo4h2o platelets: formation reaction, growth mechanism, and conversion into high-voltage licopo4 cathode for li-ion batteries - sciencedirect

A ball milling process not only affords particle size reduction by grinding but also particle synthesis induced by mechanical actions at ambient temperature. However, in traditional mechanical synthesis, it is difficult to control the particle morphology, including the size and shape, because of collision with the balls. This study shows that platelet-like NH4CoPO4H2O particles are synthesized via wet planetary ball milling and converted into a high-voltage LiCoPO4 cathode for Li-ion battery. The NH4CoPO4H2O platelets formed by the dissolutionprecipitation reaction are repeatedly ground, dissolved into a solution, and recrystallized to afford crystal growth during the milling treatment. The converted LiCoPO4 cathodes retain the precursor morphologies, exhibiting high discharge capacities for flake particles and better cyclabilities for large platelet particles. The mechanical-assisted particle synthesis in solution is a simple method for the large-scale production of morphology-controlled nanomaterials.

A grinding process that affords particle size reduction is categorized as a break-down method in powder synthesis [1]. This is a traditional and the most straightforward method to produce fine powders with the sizes of micrometer scale. Ball mills, including the recently developed high-energy planetary ball mills, are widely used for powder manufacturing as the typical grinding mills [2,3]. Although the grinding process can afford a decrease in the sizes of the particles, the treated particles exhibit lattice defects and decreased crystallinities because of the applied mechanical actions such as collision and shear with ball media [[4], [5], [6]]. However, this mechanical activation of the particle surface or interior becomes a driving force for binding other particles and the diffusing of atoms and ions. Disrupted surface bonds and increased vacancies enhance the reactivity of solids. Hence, mechanical-assisted particle synthesis at ambient temperature has been used in the past few decades in fields of metal, ceramic, and organic compounds [[7], [8], [9], [10]]. One of the limitations in the further development of this mechanical process is the control of the morphology of product particles, which is difficult because of the collision with the balls.

In contrast, solution-based processes are categorized as bottom-up methods, which involve co-precipitation, sol-gel, and hydrothermal reactions, and are beneficial in controlling the sizes and shapes of the particles. These are widely utilized in the powder synthesis for advanced materials requiring uniform morphologies [11,12]. The reaction scheme in this process consists of the dissolution of the raw materials into the solution, precipitation of the products, and subsequent crystal growth. The thermal energy input from external sources, e.g., a hot plate and an electric furnace, induces nucleation and crystal growth in the solution due to a change in the solubilities of the materials [13]. However, the thermal conductivity is heterogeneous in the solution, and thus crystal growth often requires a long holding time. Therefore, a more efficient reaction system that promotes dissolutionprecipitation reactions is needed.

The collision of balls within the solution is efficient to induce dissolutionprecipitation reactions. Recently, we applied a wet mechanical process using a planetary ball mill to produce fine particles following the reaction scheme for solution methods [[14], [15], [16]]. The planetary ball mill adds high impact energies from the collisions of the balls to the inside materials because of the high centrifugal acceleration caused by the rotation and revolution of the vessel. In wet milling, the solubility of the material varies owing to the local and instantaneous changes in temperature and pressure caused by the collision. Concurrently, the particle size reduction via wet milling contributes to the efficient dissolution of the materials. The preparation of the particles with anisotropic shapes via wet milling has been performed by employing a self-organization method using surfactants or immiscible solvents [17,18]. However, as the high-energy wet milling promotes dissolutionprecipitation reactions, the morphology-controlled particles can be obtained even by the treatment of raw materials in water [14]. The wet mechanical process can allow the variation in milling conditions such as ball size, centrifugal acceleration, treatment time, and ball/powder ratio to control the particle morphologies of the products without any additives. A prior study reported that the treatment of NH4H2PO4 and MnCO3 in water afforded ammonium manganese phosphate hydrate (NH4MnPO4H2O, AMP) with platelet, rod, and nanoparticle morphologies by only changing the milling conditions [16]. A comprehensive understanding of the growth of anisotropic particles during wet milling can provide new opportunities in particle synthesis through the dissolutionprecipitation reactions.

This study describes the formation and growth mechanism of ammonium cobalt phosphate hydrate (NH4CoPO4H2O, ACP) with platelet morphology via wet planetary ball milling. To simplify the understanding of the formation reaction of the anisotropic particles, ACP is synthesized because the platelet-shaped particles are formed in most milling conditions. The platelet shape of the ACP particles is formed by the repeating dissolutionrecrystallization reactions during milling, and the size varies depending on the treatment time and centrifugal acceleration. Furthermore, ACP can be used as a precursor to lithium cobalt phosphate (LiCoPO4, LCP) high-voltage cathode for Li-ion batteries. LCP with a stable olivine-type crystal structure exhibiting a high redox potential (4.8 V vs. Li+/Li) and a theoretical capacity of 167 mA h/g is considered as one of the promising cathode candidates for all-solid-state lithium batteries [[19], [20], [21]]. However, as with other olivine-type cathodes such as LiFePO4 and LiMnPO4, modifying LCP particles, including the size, shape, coating, and doping, is carried out because of extremely slow diffusion of Li+ and low electron conductivity [22]. A conversion route from varied precursors, including ACP, allows for a unique shape more readily rather than a direct synthesis of morphology-controlled LCP particles [23,24]. The preparation of ACP platelets via wet planetary ball milling accelerates the large-scale production of LCP powders by the conversion method. The ACP powders prepared under various milling conditions are converted into LCP and its cathode performance is evaluated. The relationship between the size and shape of LCP and the cathode performance is established. This study provides a new particle synthesis strategy that combines the conflicting processes of grinding and crystal growth.

In a typical synthesis, the stoichiometric amounts (3 g total) of NH4H2PO4 and Co(OH)2 (FUJIFILM Wako Pure Chemical Corp., Osaka, Japan) as well as deionized water (20 mL) were processed in a planetary ball mill (High-G BX254E, Kurimoto Ltd., Osaka, Japan). These were placed into a stainless-steel vessel (170 cm3) containing Y2O3-stabilized ZrO2 balls (100 g; diameter, = 2 or 5 mm). The vessel was sealed and then rotated under centrifugal acceleration of 10150 G. The centrifugal acceleration

Our previous study regarding the synthesis of AMP by milling in water described the product formed by the combination of water-soluble and insoluble raw materials [16]. To confirm this observation in the synthesis of ACP, four Co sources were tested as counter materials for soluble NH4H2PO4, i.e., soluble CoCl26H2O and Co(CH3COO)24H2O, and insoluble CoC2O42H2O and Co(OH)2. Fig. 1 shows the XRD patterns of the products after milling at 50 G for 2 h using balls with =2 mm. The results are

In summary, NH4CoPO4H2O (ACP) platelets are synthesized via the wet mechanical processing of NH4H2PO4 and Co(OH)2 in water using a planetary ball mill. The formation of ACP is achieved by the dissolutionprecipitation reaction, involving the gradual dissolution of water-insoluble Co(OH)2 into the NH4H2PO4-dissolved acidic solution. The use of Co(OH)2 with a brucite-type structure allows the ready formation of the layered ACP phase. Despite the ball milling treatment, ACP particles with

Takahiro Kozawa: Conceptualization, Investigation, Writing - original draft, Writing - review & editing. Kayo Fukuyama: Investigation. Akira Kondo: Writing - review & editing. Makio Naito: Writing - review & editing, Project administration.

This work was supported by the High Performance of Ceramics and Manufacturing Process, Adaptable and Seamless Technology Transfer Program (A-STEP) through target-driven R&D by the Japan Science and Technology Agency (JST) (Grant Number JPMJTS1615), and by the JWRI Young Researcher Grant Program. The authors thank Mr. Takeshi Murakami (JWRI) for the TEM observation.

Continuous evolution of electrode materials still has not correspond todays energy storage system necessity and limits their application range. Numerous approaches are proposed to improve lithium ion batteries (LIBs) energy density including advancement of positive electrode materials. Olivine structured cathodes as LiCoPO4 and LiNiPO4 are excellent candidates due to their working potentials of exceeding 5.0V vs. Li+/Li. Despite the efforts, these materials still have several intrinsic problems which demand various strategies to overcome. The paper systematically reviews the recent progress of these cathode materials. The approaches based on particle size manipulation via synthesis route variation and carbon addition, surface modification by coating with electron conducting carbon layer, and doping the structure with other metal ions were discussed and analyzed as the most impactful towards achieving competitive performance. Furthermore, the computational technique was discussed due to its importance in understanding and designing the materials from atomic to microscale levels. The potential applications of these cathodes in a new generation of all-solid-state Li-ion and aqueous batteries were described.

SnxFe32x/3O4 nanoparticles were synthesized using the precipitation under reflux method by Sn2+ doping (x = 0.0000.150). The structural and magnetic properties of the prepared materials were characterized using a host of techniques. We demonstrate that Sn2+ doping increases the size of the nanoparticles (1250 nm) and protects them from oxidation to the -Fe2O3 phase, making them useful for magnetic applications. Rietveld refinement data for the samples suggest that the dopant Sn2+ ions, while preferentially occupying the B sites at equilibrium, initially start with A-site occupation to maintain the charge balance. While the spin unsaturation at the surface of these nanoparticles, together with oxidation to maghemite, explains the observed decrease in magnetization of the Fe3O4 nanoparticles, it does not for the doped samples, for which spin canting in B sites was preferred.

Eu3+/Tb3+ co-doped NaLa(WO4)2 phosphor was synthesized by a hydrothermal process. The structure of the samples were investigated by X-ray diffraction. The photoluminescence spectra, photoluminescence excitation spectra, and fluorescence lifetimes of the samples were measured to investigate the luminescence properties. We analyzed the bidirectional energy transfer processes between Eu3+ and Tb3+ in NaLa(WO4)2 and gave out the explanations. By adjusting the doping concentrations of Tb3+ and Eu3+, we obtained a phosphor that emits white light. Under the excitation of 382 nm, the chromaticity coordinate of NaLa0.96(WO4)2:1%Eu3+,3%Tb3+ are (0.31,0.33) and the correlated color temperature is 6472 K, indicating that it can be used as a candidate for white light emission.

The TiO2 nanoparticles aggregation (TNA) was synthesized by a novel one-step hydrothermal method in this work. And for the first time we prepared a kind of jelly pastes of TNA used as photoanode for high-efficiency dye-sensitized solar cells (DSSCs). The prepared TNA provides larger specific surface area of 79.34 m2 g1 compared with P25 nanoparticles (49.25 m2 g1), which is beneficial of absorbing more dye molecules and contributes to high current densities. Moreover, the high scattering effect of TNA caused a strong absorption in the visible-light range increasing the number of excited charges and reducing the energy loss. The effect of various concentrations of TNA pastes for DSSCs was studied to explore the superiority of concentrated TNA pastes. The result shows the DSSC based on high-concentration pastes and double-layer film achieved the best power conversion efficiency (PCE) of 8.34 % corresponding the current density of 17.97 mA cm-2.

Nanosized LiFePO4 particles, each covered with a complete but thin carbon shell, are synthesized via a solgel process using citric acid (CA) as both chelating agent and organic carbon source in this study. Several precursors are prepared with various mole ratio of CA to total metal ions (nCA/nm) first. Then the prepared precursors are investigated by thermogravimetry and derivate thermal analysis. The LiFePO4/C samples obtained via calcining the precursors at different temperatures are characterized by X-ray diffraction, field emission scanning electron microscope, transmission electron microscope and galvanostatic charge/discharge test. The systematic study shows that the LiFePO4/C nanocomposite, calcined from the precursor with a composition of nCA/nm equal to 1:3 at 650C, delivers discharge capacities of 166 and 153mAhg1 at 0.1 and 1C, respectively, and exhibits almost no capacity fade up to 50cycles.

H4FePO4H2O is synthesized by both co-precipitation and rheological phase methods. The as-synthesized compounds have been characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The electrochemical properties of NH4FePO4H2O as anode were initially investigated with a comprehensive battery testing system. The results showed that NH4FePO4H2O featured different electrochemical performances as synthesized by the two different methods. The NFP-1 sample synthesized by co-precipitation method had higher initial capacity (1406.8mAhg1) than that of the NFP-2 (1247.9mAhg1) sample synthesized by rheological method. After 100 cycles, NFP-1 showed higher reversible capacity (523.4mAhg1) than that of NFP-2 (210.3mAhg1) within the voltage range of 0.01 to 3.00V (vs. Li+/Li) at current density of 100mAg1. The results suggested that NH4FePO4H2O prepared by co-precipitation is a novel and promising anode material for lithium-ion battery application.

Currently, multi-dimensional scale controllable preparation of energy nano-materials is an important strategy to achieve high performance. To solve these issues, nano-structured lumpy particles and thin sheets of ammonium manganese phosphate hydrate (NMP) were designed and fabricated by facile solid-state reaction at room temperature and co-precipitation method, respectively. When used as anode for LIBs for the first time, the lumpy particles exhibits better electrochemical performance, such as higher discharge capacity, better cycling stability, rate capability, compared with the thin sheets NMP. For example, the lumpy particles NMP electrode delivers a high reversible specific capacity of 1307 mAh g1 at 100mAg1 after 350 cycles, while the other NMP electrode presents only half. The excellent performance of nano-structured lumpy particles NMP can be ascribed to the smaller longitudinal-transverse ratio of lumpy particles and porous structure.