The Exact Makeup Of The. Two Grinding Complement Ball Method Was Developed And Applied Research

Ore grinding is the leading operation in ore dressing plants.The capacity rate of processing original ore in workshops in the plants actually is decided by the productivity and processing ability of ore grinding.The quality of the grinding products gravely affects the targets of ore processing.For example increasing the mineral monomer separation degree and decresing the overcrushing of mineral can increase the grade of concentrates and recovery of useful mineral,reduce run off useful mineral of the metals and raise a percolation efficiency mineral separation plants etc.Among many processes or methods of improving grinding effect,the most actual meaningful one is to grasp grinding media factor to make grinding effect improved completely.This is because of grinding workshop section to lie grinding media.However, grinding media is lie many factors for the size and shape of media,capacity of mills, distribution ratio of media,reasonable add steel ball system and revolution speed of mills etc.The group development the method of accurate ball-load-addition in single stage grinding from 2003 to 2005 and show the effect after some plant apply:①The mill's productivity has increased by 10～20%in the case of the same grain size distribution of the mill's feeding and discharging.②The mineral unit separation degree has increased 5～6%on condition that the size distribution of the grinding products has not changed.③The recovery has increased 1～3%and the concentrate grade also risen on the same ore dressing condition.④The consumption of steel ball has decreased by 10～20%for the same quality ball.⑤The unit electricity consumption of grinding has decreased by 10～20%for the same ball loading system.⑥The mill's noise has descended more than 5dB.⑦The life of grinder's lining board has prolonged 30%.But apply this method to the two stage grinding,the capacity of ball mills significantly lower.Thus the method of accurate ball-load-addition in single stage grinding is unsuitable to the two stage grinding.For this,deeply expanding and developing suitable accurate ball-load-addition method for two stage grinding is the main research contents of this thesis.This thesis first studied the mechanics property of the grinded ores,including the hardness,roughness,cleavage and structure faults.Hard and rough ores are difficult to be grinded,the cleavage phenomenon and structure faults ore easy grinded.Therefore aiming at the mechanics characteristic of ore and fitting it with grinding condition will have a good ore grinding effect.The mechanics property of ore depend on crush dint of dissimilarity express an anti- crushing function,generally mean rocky opposite and hard with"hardly coefficient".The compressive strength limit of ore is divided into the regular ore and natural ore.The compressive strength limit of regular ore above 10mm must be revised and calculated by converting the volume of the ore to the compressed area method.Therefore, the anti-crushing mechanics property research of ore enhanced the aim of grinding,and provide for the necessary of parameter data and mechanics basis to precision computed ball diameter.Steel ball is the implement body which grinding function and the deliver of energy body.It decide the broken up behavior of ore can take place and how take place,influence produces ability of mills,the quality of the grinding quantity(include grain degree characteristic,monomer separation degree characteristic etc.)and steel consume and energy consume etc.But the factor of the influence steel ball size be a lot of,how the precision compute steel ball the size be the problem to resolve.The thesis emphasized on introducing Duan's ball diameter semi-theory formula,which can give precise diameters of balls needed under the particular conditions at rough and fine ore grinding.The two stage ore grinding because of its grain,the destructive power,pulp concentrates,the shape of media etc,has a paticular request to the accurate medium ball diameters.Ball diameter semi-theory formula only solved the problem which calculation single narrow grain size diameter,for feed for hybrid grain size,the steel ball has to make sure the comparison of of the grain size and each size of pack the ball,this depend the loading ball to resolve.This thesis according to the research method of crushing statistics mechanics, don't study the sport regulation of single steel ball,but the crushing behavior of the aggregation which passes to study single steel ballcrushing function of mineral grain.Use fall in pieces affairs' quantity to measure quality of grate the effect.For single diameter of crushing statistics mechanics,can make sure the best diameter and identify the accuracy of ball diameter semi-theory formula.For mixture ball set of crushing statistics mechanics, can provide basis for loading balls in mills.The beginning loading balls only solved the pack a ball problem before mills working, as soon as mills work,the steel ball wears away to immediately produce,immediately be repair problem of adding ball.Traditionally and in brief pack to repair ball method and reasonable balance method,because of it of the blemish make these two kinds pack to repair a ball method hard carry through to performance or ineffective.So far not a mathematics model which purely and theoretically mill ball to wear away regulation,so the adding ball impose physically in operation don't easily carry out.For this,this thesis useds to a diagram method to carry out steel ball of reasonable repair to add.Compare reasonable balance add a ball calculation without twice pure ball,and loading ball and adding ball to compute a completion,saved a great deal of work and time.In the two stage fine grinding,this thesis puts forward an new wearable iron sect medium as a substitute for traditional steel ball,and the contrast experiments show the new fine grinding media effect is better than that of the mixture ball set and of hybrid iron sect set.In rough stage,daptability research of the method of accurate ball-load-addition by increasing revolution speed of rough mill,can give a conclusion of the method can use and must adjust the amount of balls.From the above research,this thesis deeply expand the method of accurate ball-load-addition for two stage grinding.According to the mechanics property of ore determines accurate steel ball size.Using crushing statistics mechanics principle the category and ratio of balls.According to diagram method carrys on accurate simplely adding balls.Using higher revolution speed in rough mills in rough stage.Using short head cone iron sect acts as fine grinding media.The method is applied in Shizishan Copper Mill in 2005.The conclusions are:①The grinding's productivity has increased by 9%from 76.46t/h to 83.34t/h for a grinder.②The fineness of grinding products(-200 mesh)has increased by 7.88 percentage points from 76.41%to 84.29%.③The ore grade decrease from 0.72%to 0.67%and concentrates grade has been increased 0.66 percentage points,the recovery increases by 2.98%.④The electricity consumption decreased by 10.81%.⑤The grinding media consumption decreased by 10.42%.So the method of accurate ball-load-addition for two stage grinding make mill's production has increased from 1850t/d to 2200t/d and attain an expectation target.The adaptability research of the method of accurate ball-load-addition for two stage grinding in rough grinding by increasing revolution speed has been carried out.The conclusion show:①The grinding's production has increased by 20.12%from 76.46t/h to 91.84t/h for a grinder,increased 10.20%as last year.②The first stage electricity consumption decreased by 17.92%and plant electricity consumption decreased by 21.33%.③The grinding media consumption decreased by 31.64%.From here get conclusion,the method of accurate ball-load-addition for two stage grinding can still keep use after increase revolution speed(low in 88%),make mill's production has increased from 1850t/d to 2200t/d in Shizishan Copper Mill.But increase revolution speed must decrease the pack amount of ball and make pack amount of ball response to revolution speed.A scale 2200t/d of medium-sized mill after adopting the accurate ball-load-addition method,the economic performance reaches to 71,519,800 dollars in 30 months.In 2007, the yearly economic increases is 42,981,100 dollars and the economic performance shows very well.Industry experiment and applied effect confirmation show that the development of the method of accurate ball-load-addition for two stage grinding effects well and is worthy of expansion as a new technique.