Rolls, crushing with

Chandler [Bull. Br. Coal Util. Res. Assoc., 29(10), 333 (11), 371 (1965)] finds no good correlation of grindabihty measured on 11 coals with roll crushing and attrition, and so these methods should be used with caution. The Bond grindability method is described in the subsection "Capacity and Power Consumption. ... 

Some authorities favor carrying roll crushing down to H 5 of an in. but the limit for these machines is today owing to other practical considerations about K in. At one time there was and there is still an active school which advocates taking material directly from large crushers and feeding it to ball mills for reduction to sand sizes. This practice led to some disastrous deficiencies in expected tonnages. The tendency today is to consider material 1 in. in size and smaller as the maximum in point of size which should be fed to ball mills. As to whether coarser material can be fed with satisfactory capacities will depend upon its hardness. 

If the potassium or sodium chlorate is lumpy, remove all lumps by crushing with a rolling pin. Using the spoon, add an equal quantity of chlorate to the container. 

Fig. 9.6. A cane mill with its three crushing rolls and with a typical turn-plate arrangement. A hydraulic piston maintains pressure on A, while B and C are fixed. The rolls are under pressure of 75-80 tons per foot of roll width.

Primaiy crushers used are jaw, gyratoiy, impact, and toothed roll crushers. Impact mills are hmited to hmestone and softer stone. With rocks containing more than 5 percent quartz, maintenance of hammers may become prohibitive. Gyratoiy and cone crushers dominate the field for secondaiy crushing of hard and tough stone. Rod mills have been employed to manufacture stone sand when natural sands are not available. 

Finisli-Grinding of Cement Clinker Typically the hot clinker is first cooled and then ground in a compartment mill in closed circuit with an air classifier. To crush the chukers, balls as large as 5 in may be needed in the first compartment. A roll press added before the ball mill can reduce clinkers to a fine size, ana thus reduce the load on the ball mills. The main reasons for adding a roll press has been to increase capacity of the plant, and lower cost. 

Owens, J. S. Trans. Inst. Min. Met. 42 (1933) 407. Notes on power used in crushing ore, with special reference to rolls and their behaviour. 

The only significant difficulty in processing occured at carding where static electricity caused the web to behave erratically. The static was controlled by carding the cotton with a static bar in place under the web just as it exited the crush rolls. Processing and yarn quality results for the 3 cottons made into 19.7 mg/m yarns at 13000 rpm spindle speed are shown in Table X. Spinning quality results for the Mississippi and California cottons that were made into 14.8 mg/m yarn are shown in Table XI. 

Crush the RNA bands in a mill (A11 basic analysis mill, IKA), and poured it into a 50 ml polypropylene conical tube with about 30 ml Millipore water. Place the tube in a rock and roll stirrer at 4°C overnight. 

CA 73, 47182h(1970) (Fine AN granules resistant to moisture and abrasion were obtd by roll-compressing AN contg 2.4% water at 2—25 tons/cm2 and crushing to 0.5— 3mm particle size. The granules were soaked with liq expl, or a C carrier such as Diesel oil.)... 

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