Advanced Materials Research Vols. 361-363

Abstract: The purpose of this work was to investigated the carbothermic reaction of fluorapatite process by the means of thermodynamics analyses, XRD and element analysis, respectively. Thermodynamic calculations indicated that phosphorus can be prepared by heating the mixture of Ca₅(PO₄)₃F₂ and C at 1173K under the system pressure of 100Pa. CO cannot react with Ca₅(PO₄)₃F₂ in the carbothermic reduction process at 973-1873K and 100Pa. Experimental results demonstrated that phosphorus can be produced by the reaction between Ca₅(PO₄)₃F₂ and C, the main reaction phase is P₂(g), CO(g), CaO and CaF₂, and with increasing temperature, the greater degree of response. The best technology conditions, the molar ratio of Ca₅(PO₄)₃F₂ to C is 1:7.5 at 1723K for 1h when the system pressure was about 100Pa. This study to provide experimental evidence for preparation of phosphorus by carbothermal reaction of fluorapatite in vacuum.

Abstract: According to the nature of a polymetallic ore and on the basis of the main separation of the molybdenum minerals, the low-grade bismuth, tungsten minerals with be associated are to be recycled. The beneficiation process of Mo-Bi bulk floatation separation and tailings bulk floatation followed by scheelite floatation was determined through a lot of testing. The indexes of small-scale closed circuit test were obtained: the molybdenum concentrate grading at 52.82% with a recovery of 95.01%, the bismuth concertrate grading at 15.26% with a recovery of 53.94%, the scheelite concerntrate with WO3 31.5% and recovery 37.27%. The result of research laid a technical foundation for the raising the comperhensive utilization ratio of mineral resources in the mine.

Abstract: This document explains the pollution source from gas stations, including fuel evaporation, leak of fuel and discharge of waste water from cleaning tanks. Then it puts forward preventive measures, i.e. lessening fuel evaporation by improving operation methods, recovering fuel vapor by fuel vapor recycling system, revamping and updating facilities to prevent leak of fuel and the waste water from cleaning tanks should be properly processed before discharging.

Abstract: The paper researched on hematite’s characteristic of process mineralogy in Fengyang Anhui province. The chemical compositions of the ore were analyzed. The species, components of the hematite are determined, and the grain size and embedded characteristic of the ore are statistical. Some suggestions are proposed to improve the recovery of Fe₂O₃ according to the result of the process mineralogy study.

Abstract: Using scanning electron microscope, the microscopic pictures of the surface on sediment have been obtained from the sub-micron titanium dioxide suspensions without dispersant or adding different types of dispersants. Deposits of titanium dioxide suspension have been observed and the mechanism of the dispersant has been analyzed. Meanwhile, deposits of titanium dioxide gray distribution figure have been gained by self-compiled Matlab program, which proved that the surface sediments is fractal, and the fractal dimension has been calculated under different conditions. The rules between suspension stability and fractal dimension have been achieved.

Abstract: There are lots of problems in coal flotation reagents. For example, it was difficult to disperse in coal pulp, it needs a large consumption, and its selectivity was poor. So this paper refers that kerosene can be made into compound kerosene by using different chemical products and surfactants, and then used for coal flotation. Tests proved that compound kerosene can disperse in coal pulp quickly; they had a high yield of clean coal, a fast flotation speed and a higher flotation perfection index. As a result, the flotation effect of Fy-6 compound kerosene was the best of all. Clean coal zeta potential of Fy-6 compound kerosene and kerosene had been tested, and they had been compared with raw coal.

Abstract: The status of coking coal resources and the utilization of the middlings of coking coal are analyzed in this paper, and the necessity and practicability of middlings’ rewashing is held up. Middlings of BaBao Industrial Park Coal Preparation Plant is used as sample of experiment test, through size analysis and float-and-sink test, the feasibility of middlings’ rewash is demonstrated. Two kindes of separation processes are presented : ⑴crushing-coarse and thin slime are separated separately; ⑵crushing-grinding-froth flotation. Scheme 2 is appropriate for the separation of Babao middings.Experiments confirm that the scheme 2 would be more suitable for the middlings’ separation, and the cleaned coal’s production rate of is 31.88% , the ash content is 14.4%. So there are high social benefits and economic benefits. Reclean middlings of coking coal is a new direction for the protection of coking coal resources, in the meantime, it comply with the environmental requirements and is an important measure to realize the sustainable development.

Abstract: Orthogonal test was carried out to investigate effects of multiple factors during the magnetization roasting-magnetic separation process as follow: roasting temperature, time, ratio of reducing agent and magnetic field intensity. Significant order of those factors on grade of iron concentrate is obtained, and opportune condition for magnetic roasting is determined. As the condition that roasting temperature is 850°C, time is 40min, ratio of reducing agent is m_coal/m_ore=12% and magnetic field intensity is 1800Gs, iron ore concentrate whose grade and recovery are 56.32% and 94.03%, respectively, is obtained. At last, through closed-circuit test including magnetization roasting, magnetic separation and reverse flotation, final result is obtained that iron concentrate with phosphorus and silicon are 0.18% and 2.63%, respectively, and its iron grade and recovery are 60.47% and 80.1%, respectively.

Abstract: Recovering gold form arsenic bearing gold mine through floatation has always been an important research subject, the gold ore contains 2.40 g/t of gold and content of arsenic was 1.2% in Hebei, cannot achieve good product indexes, in order to improve the efficiency of resource use, lime was adopted to control the pH value of pulp, NaHSO₃ was added to inhibit the arsenic, the floatation of gold was carried out priority. The gold concentrate contain 65.63g/t with the recovery was 89.92% and the content of arsenic was only 0.07% after closed-circuit experiment, that results means the product indexes were improved greatly compare the field product now.

Abstract: This paper introduced a newly developed coal flotation collector ZFC and its flotation characteristics for Shanxi three different coal samples. ZFC was an emulsion composed by 27% diesel oil, 70% water and 3% homemade surfactant PGS. The surfactant PGS was synthesized with environmental friendly reproducible oil and several surfactants. The flotation results showed that the ZFC had the characteristics of excellent performance, high selectivity and good stability. ZFC could promote the dispersion of diesel oil in the slurry, so that the efficiency of floatation was improved and about 70% diesel oil was saved.