Research On The Comminution Technological Process And Equipment Modification In The Alumina Production

This article describes the process of crushing& milling system in Alumina Refinery,Shandong Aluminium corporation,and points out its existing questions in the present process of first-segment crushing and second-segment milling.With the low efficiency due to 30mm or so of inlet granularity and with Alumina capacity increasing continuously,the throughput of ball mill is insufficient which restricts the product-increase greatly.Unnecessary crushing needn't be done according to traditional crushing& milling principle. With the development of modern industry,scientists tried to unite crushing and milling together and lodged the principle of more crushing and less milling.But a new principle of crushing instead of milling is reached according to the fine of minerals machining and development of crushing physics and chemics.By research on crushing& milling technology at home and abroad,an unique combination of crusher,roller mill and ball mill is achieved especially for SALCO which can solve the question that ores couldn't be crushed and milled easily before and make each unit combines the newest crushing& milling with industrial production.This article analyses crushing theory and the configuration and work principle of roller mill, the development of its technology,the influence on productivity and energy consumption of roller mill particularly several main factors(granularity, pressure,rotating speed and moisture of materials),and concludes the change rules of its throughput and energy consumption by using mathematical statistics after substantive industrial trials.To solve the question that single objective function can't reach maximum simultaneously under the same technical conditions,comprehensive index functions are quoted for the most economy and best application.Inlet granularity of ball mill decreases from original-15.7mm of P80 to-5.3mm,crackles inside the particles increase,materials can be milled easily.To adapt to the change of material property,corresponding alterations are done to ball mill after discussing the impact crush theory and optimal inlet granularity:1.to alter the feeder of ball mill;2.to regulate the ratio of balls to segment cubage and filling rate of bal;3.to reduce three storehouses to two etc.Finally,the throughput of ball mill can rise by more than 36.23%and energy consumption reduce by 26.64%,a new breakthrough is attained which is in the leading class at home.This article validates it is correct to apply crushing instead of milling by process alteratins for crushing& milling process in Alumna Refinery of SALCO and by feasible study and trials on bauxite pre-milling process of roller mill.It validates primary that new ultra-fine equipments of high efficiency and energy consumption,i.e.high pressure roller mill,can increase throughput greatly and decrease consumption of electricity and steel.Simultaneously,it provides a reasonable equipment collocation and optimal parameter selection for industries',renewal or altering ores crushing and milling system.