Experimental Study On Griding Process Optimization Of Shizhuyuan 1500-tpd Polymetallic Mineral Processing Plant

Due to the value mineral variety, complex components and metasomatism, close symbiotic relationship, fine dissemination, so the demanding of the Hunan Shizhuyuan grinding fineness is very fine. However, the fineness would led to extremely serious over crushing and low comprehensive resources recovery. Grinding production inhomogeneity is prominent, steel and power consumption, liner wear, grinding production cost are high, because of unreasonable grinding system of 1500t/d Shizhuyuan polymetallic mineral processing plant.Through the grinding-classification circuit of Shizhuyuan polymetallic mineral processing plant study, it showed that the rate of particles of the overflow fineness of-10μm from the second stage of classification is as high as 16.30%, the grade of metal and metal quantity are also respectively up to 0.43%, 21.93%, and over crushing is serious, which are the major cause of low comprehensive resource recovery. In order to solve the above problems in grinding-classification system, optimization-precision tests of grinding system were conductedn in this paper.Studied the mechanics characteristic of minerals, the results showed that the compressive strength of is 1069.84 kg/cm2, protodikonov’s hardness coefficient of rock f is 10.7, which belongs to hard ore. But the poisson’s ratio of irregular ore block is between 0.12 ~ 0.174, far less than 0.24, it indicated that Shizhuyuan ore is brittle, and there would be fine powder at comminution processing.By the compressive strength of irregular ore block formula and half-theory of ball diameter, the biggest calculative ball diameter is 80 mm less than the original ball-load-addition in 100 mm. The studied showed that the main causes, which leading to overflow over crushing at the second stage of classification, are the ball diameter too large which can lead to penetrative broken.The influential factors experiments of grinding process showed that the fineness of first stage grinding product was 47.15%, over crushing γ-10μm was 11.60% and grades of qualified grain fractions γ74~10μm was 35.33% under optimal parameters: grinding time is:4 minters, grinding concentration is: 70%, and mill revolution rate is:85%; the fineness of second stage grinding product was 31.65%, over crushing γ-10μm was 6.21% and its grades of qualified grain fractions γ74~10μm was 25.44% under parameters: grinding time is:6 minters, grinding concentration is: 65%, and ball filling rate is: 38.5%.The successful laboratory results and optimum process parameters provided the basis for the industrial promotion test. The industrial test showed that we can obtain good experimental effect, increase efficiency and save energy under the accurate grinding with capacity of 92 t/d, the growth of 6.53% more than before; under the invariable fineness, the over crushing of overflow from second stage of classification reduces by 4.88%, grades of qualified grain fractions increases 4.96%, steel balls consumption reduce 0.101 kg/t and power consumption reduces 8.681 kw/t. At same time, the recovery rate of tungsten, molybdenum and bismuth respectively increased by 0.79%, 0.88% and 0.37%.