Advanced Materials Research Vols. 524-527

Abstract: The structure of filter cake obtained by the positive horizon pressure filtration process has more advances. The paper investigated some main influencing factors about feed concentration, filtration pressure, feed grain composition on dehydration effect. And paper designs the testing program and analyses the testing results. Then paper establish the mathematical model about the filter cake moisture, filtrate concentration, the capacity of handling dry slime and the experiment influence variables. The results show that the filter mass moisture decreases as the increase of feed concentration, filtration pressure and feed size. At the same time, the filtration time, filtration pressure and feed concentration have a little influence on filtration concentration, and handling capacity of dry slime has a proportion with feed concentration and filtration pressure and has a inversely-proportional relationship with filtration time.

Abstract: The inchoate algorithm for the coal slime flotation control is the feed-forward control to the feed concentration and the reagent quantity. This control model is widely utilized because of the easy realization once the used sensors are reliable. However the control results are usually not so good as it cannot adapt the quality fluctuation of the feed, obtain the on-line quality of the feed and the products, and also cannot statistically calculate the flotation recovery and other production management information. The appearance of the coal slurry ash detector provides the new method for resolving the problems above. This paper studies how to increase the production rate and decrease the reagent consumption through the optimizing control under the premise of the accepted concentrate ash. The industrial application of the intelligent and optimal control of the coal slime flotation results in a high concentrate recovery and a decrease of the reagent consumption, ensuring a highly efficient operation.

Abstract: In this manuscript, the effects of the regeneration temperature and oxygen concentration on the regeneration behavior of modified semi-coke supported (Fe, Zn, Ce) sorbent were investigated using a fixed bed reactor and a thermogravimetric analyzer. Sulfate formed through side reactions was inferred from TGA curves and it can be reduced by increasing the regeneration temperature. The reasonable regeneration conditions must avoid the sulfate formation. Regeneration kinetic studies were also performed at regeneration temperatures ranging from 500°C to 700°C. The results show that the regeneration rate can be improved by increasing the oxygen concentration and regeneration temperature. The reaction order of regeneration with respect to O2 can reasonably be assumed to be first-order. The kinetic model tests show that the shrinking core model can be used to correlate with the experimental data. The regeneration is controlled by the chemical reaction in the early stage of reaction (x＜80%) and by the diffusion through the product layer at the latter stage (x>85%). According to the model, the apparent activation energy of chemical reaction and the corresponding frequency factor are 16.66kJ/mol and 0.132m/s, respectively, and the diffusion activation energy and the corresponding frequency factor are 52.91kJ/mol and 6.63×10-5m2/s, respectively.

Abstract: With the exhausting of lead–zinc sulphide ores, the recovery of lead-zinc oxide ores becomes more and more significant. Extensive work has been carried out at home and abroad on the treatment of lead and zinc oxide ores in reagent scheme, flotation flowsheets, and joint process. Sliming is one of the main reasons why the lead-zinc oxides are difficult to recover. Eliminating the influence of slime and strengthening the study of joint process are the main development trends in future work.

Abstract: Based on process mineralogical study of a low-grade Cu-Ni-platinum group metal(PGM) sulfide ore in SW China, the occurrence of Cu and Ni, the distribution of platinum group minerals (PGMs) and their relationships with other minerals are determined in detail, which provides scientific reference for forthcoming mineral processing and extractive metallurgy. The mineralogical results show that 18 individual PGMs containing all the 6 platinum group elements (PGEs) are investigated, and it can be concluded that the PGMs in the ores mainly occur as individual minerals. SEM images show that the PGMs are mainly disseminated in sulphides, most occur as inclusions or semi-inclusions, and part are inlayed along the other minerals to form coarse compound grains. Due to the the complex mineral composition and texture, processing the Cu-Ni-PGM ores by traditional flotation may be difficult to get a good processing performance.

Abstract: Based on the analysis of the properties of the ore from Weixin area in Yunnan province, a suitable technical route was presented for the processing of sulphur concentrate with high quality. The main factors i.e. grinding fineness, pH, collector type and dosage, affecting the quality of roughing concentrate was investigated. On this basis, a close-circuit flotation test scheme was proceeded, which obtained a high quality sulphur concentrate with sulphur grade of 51.58%, sulphur recovery of 99.22%, iron grade of 45.14% and impurities content of 3.28%. In addition, a decrease of slurry concentration of cleaning further increase the quality of sulphur concentrate, which contained 52.82% sulphur, 45.29% iron and 1.89% impurities.

Abstract: The joint technics on sodium jarosite process and solvent extraction technique for lixivium of nickel laterite ores has been investigated. The results indicate that a Fe₂O₃ product with Fe grade of 58.12% could be obtained by precipitation separation and roasting, the total recovery of iron reaches 94.87%.Under the conditions of extracting temperature for 30°C, phase ratio 1:1, blance time 10min, pH = 5.5, the percentage extraction rate of Ni reaches 99.04%. When the 3 mol/L H₂SO₄ solution was used as stripping agent, the stripping rate of Ni reaches 97.52%. The total recovery of nickel reaches 94.56%.

Abstract: The study aims to recovery of silver minerals from zinc leach residue by flotation method with mixed collectors, namely, ammonium dibutyl dithiophosphate (ADD) and diethyl dithiocarbamate (DD). The effect of key parameters, i.e., grinding fineness, dosage of collectors and dosage of sodium chloride on the flotation performance was investigated. The results indicate that dosages of ADD and DD have both significant effects on the flotation performance, and sodium chloride plays an important role in the increase of the grade of silver, by eliminating the detrimental effect of Zn2+ in the pulp. The optimum conditions for flotation of silver from the material were identified as grinding fineness of 90%, dosage of ADD at 400 g/t, dosage of DD at 75 g/t and dosage of NaCl at 60 g/t; under such a condition, a sliver recovery of 76.92% with a concentrate grade of 2012.30 g/t was achieved, and the tailing from the flotation has a lower sliver grade of 17.30g/t, with only 15.04% of silver lost in the tailing.

Abstract: Tangdan copper oxide ore deposit, located in the northeast Yunnan province of China, is the largest independent copper oxide deposit in China. The ore from the deposit is characterized by low grade, high oxidation ratio and fine-grained dissemination, which results in the poor flotation recovery. The analysis of plant flotation data reveals that the loss of copper minerals into tailings is mainly with coarse size fraction, due to its insufficient liberation and finer size, especially for the size fraction below 10 microns, which are very difficult to be floated with conventional flotation methods. In order to improve the flotation performance of the ore, laboratory tests include Hallimond flotation and vacuum flotation were respectively conducted with pure malachite, the dominant copper oxide mineral in the deposit; and the results indicate that a finer grinding fineness up to -325 mesh even -400 mesh is required to decrease the copper loss in the coarse size fraction, and vacuum flotation provides a promising way for the recovery of ultrafine malachites.

Abstract: Low-grade diatomite earth, such as the tailings generated in the diatomite mining process, can be purified through the laminar film separation process. The paper presents an investigation of the control system of diatomite laminar film separation process, and the control system has been applied in the pilot experiment. The pilot experiment results show that the diatomite and impurities have been effectively separated under the laminar film separation control system, which laid the foundation for the continuous, efficient and automatic industrial production.