The soot in the crystallization tank and the bag filter is characterized by a high arsenic content (about 63 to 49% ) and requires special handling. About 16% of the Au is transferred to the dust of the dry scrubber and the electrostatic precipitator. These soots are almost identical in terms of their chemical composition. Analysis of the forms of arsenic in these soots indicates that approximately 92% of the arsenic is arsenic trioxide. According to previous tests, the possibility of simultaneously treating the soot in the precipitator and the electrostatic precipitator with the pre-granulated raw material was verified. The above-mentioned soot was placed in a disc granulator having a diameter of 500 mm to form pellets. Disk speed of 14-16 revolutions / minute, angle of 52 ~ 55 °, only need to add water when granulated without adding a binder. The particle size selected according to the conditions which can ensure the liquid layer of the material in the furnace is 100% - 5 + 1.0 mm. The coarse particles have a moisture content of 10 to 12% and a strength of -1.1 to 1.5 kg per particle. The proportion of the dust in the dust collector and the electrostatic precipitator should be determined according to the weight of various soot produced during the roasting process. The mixed soot is then sent to a granulator for granulation. Both the roasting of concentrates and the return of soot are based on previously established systems. Stage I fired per unit of processing capacity of 90,000 tons per day and night / square meter. Before the material balance is established, the amount of the returned soot mixture should be 19.5% of the concentrate weight , which is the value of the calcining unit's reduced ability to treat the original concentrate. The roasting work is characterized by stable temperature and air conditions; the quality of the slag is very good. Second soot obtained leaner containing gold, about 5 to 3%. The yield of the slag is increased to 59-62 % of the concentrate weight . The results of the semi-industrial test show that the entire dust removal system including the dust collector, electrostatic precipitator, crystallization tank and bag filter can ensure the dust removal rate of the gas reaches 99.9% (see Figure 6 ). In the two-stage roasting method Dala Song beneficiation plant is not only practiced by: improved technology offers the possibility of economic indicators, but it is also possible to achieve local output of precious metals. 2000Kg Mini Excavator,Hx20 Mini Excavator,2 Ton Excavator With Ce,Mini Hydraulic Wheel Excavator Shandong Lixu International Trading Co., Ltd. , https://www.sdhxmachinery.com