cement mill grinding media calculation

calculation of the grinding balls assortment for the cement mill

Summing up the year 2020, we can very calmly state that Energosteels grinding balls compete with similar products of world producers. Thus, we have significantly increased sales in the foreign market. At the beginning of 2021, we received several requests to calculate the grinding balls assortment for the loading into ball mill. In this article, we will consider the one of the requests from a company based in Yemen that specializes in cement production.

Inside diameter: 4.2 meters Total inside length: 13 meters Production capacity: 7510t/h (Closed circuit, ordinary carbonate cement, specific surface area: 320m2/Kg) feeding size5mm, moisture0.5%, air speed in mill 0.5m/s. Mill rotary speed: 15.80.1r/min Charging capacity of grinding medium: 230 ton.

The raw material for cement production has a high abrasion rate. Consequently, when calculating the assortment the balls with increased volumetric hardness have been taken into account. Into the first chamber of two-chamber mill is loaded with balls from 80 to 40 mm in diameter. The second chamber is loaded with balls from 40 to 25 mm in diameter.

Into the first chamber: 80mm 53 tons, 70mm 33 tons, 60mm 10 tons, 50mm 10 tons, 40mm 3 tons. The average diameter of this assortment is 71mm. The current loading shall be carried out with a steel ball of 80 mm;

Lets remind that to receive free advice on calculating the assortment of grinding ball, you may visit our website and fill in the necessary fields. The specialists of our company will make the necessary calculations and will contact you in the shortest possible time.

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Dear Experts, I want to know about the GM size wise percentage distribution in a 2 chamber close circuit OPC ball mill. Mill dim. 3.4 x 12.5 Media load 128 MT high chrome Also let me know how do the supplier selected 80mm as max. Ball size in this mill? Please share the formula as well. Clinker feed size is 25mm with standard BWI & sp. gravity.

H there, These are just the basics if you want to accurately do it you have to fill it up to 80% BC and then do alongitudinal sieving and then correct the BC based on the results. The biggest ball determination is explained and it is based on material hardness and biggest size. Let me know if you need more info. Regards; FJalali

Thank you very much sir for this help. I was keen to know the media surface area in 1st and 2nd compartment also. You document helped me in knowing that also. Sir, Can you share the grinding balls standard surface area to be kept in raw mill and coal mill (monochamber)?

Dear Sagarhbt, Why are you concerned about surface area? I never hear about basing your ball charge on surface area! In your first compartment the grinding is not related to surface area at all and it is related to weight and number of impacts. In the second compartment the grinding is related to pass of contact or length of circumference (see attachment). But you should figure the ball charge base on how it is grinding along the length of the compartment. As I said before charge 80% of the weight base on one of the recommended ball charges and then take longitudinal samples and adjust based on the results. Let me know if you nedd ant help. Kind regards; FJALALI

Dear Sagarhbt, Why are you concerned about surface area? I never hear about basing your ball charge on surface area! In your first compartment the grinding is not related to surface area at all and it is related to weight and number of impacts. In the second compartment the grinding is related to pass of contact or length of circumference (see attachment).

But you should figure the ball charge base on how it is grinding along the length of the compartment. As I said before charge 80% of the weight base on one of the recommended ball charges and then take longitudinal samples and adjust based on the results.