Advanced Materials Research Vols. 962-965

Abstract: Titanium-bearing blast furnace slag in which TiO₂ content reaches to 20%~23% is a kind of precious secondary resource. The research utilizes the stable characteristic of TiO₂ in hydrochloric acid to digest acid-soluble matters in slag. Titanium-bearing slag is obtained after solid-liquid separation process. The optimum acidolysis reaction condition can be known through analysis of raw material granularity, acid-slag ratio, reaction temperature and effect caused by reaction time on TiO₂ content in slag. XRD image analysis can prove that the chemical compounds of Al、Mg、Fe are totally acid-thinned and TiO₂ content in slag reaches to above 40%. This technology provides a valuable new way for the comprehensive utilization of titanium-bearing Slag.

Abstract: Yunnan Dianchi surrounding areas’ phosphate rock is rich in resources, but high grade phosphate rock is less and less. Currently used methods are mainly floatation concentrate, but most of phosphate rock are difficult to flotation of collophane with fine particle size distribution. It requires grinding to negative 90% fineness of 0.074mm content for flotation. The existing grinding system is difficult to maintain the stability of the grinding fineness and steel consumption is also large, so it can’t reach the design capacity of flotation plant. This article reference in other minerals as grinding medium steel forging successful application and to explore the application of the grinding system in the collophane from dianchi areas. The experiment of laboratory can stabilized the grinding fineness, reduced the excessive grinding and the consumption of steel, achieved good results.

Abstract: In order to explore the influence of coal slurry properties on particle settling velocity, orthogonal tests with four factors in five levels concerning coal slurry concentration, proportion of -45μm fine content, pH value and water hardness were conducted without consideration of interactions using SPSS 19.0 software with coal slurry suffering difficult to sediment problem from Jisan coal preparation plant on the basis of a clear knowledge of slime mineral composition there. Furthermore, an introduction of SPSS’s application in design and analysis of mineral processing experiment is made in this paper.

Abstract: To fully evaluate the usability of a raw Ca-bentonite source and to deeply understand the property of bentonite mineral are critical for applications of these special layered materials. Due to sodium bentonites have several advantages over calcium bentonites, especially in expansibility, cation exchange capacity, cohesive force, dispersibility, and thermostability, sodium-modification of Ca-bentonite is regarded as a top priority of effective utilization of abundant Ca-bentonite source in China. In present work, the purified Na-montmorillonite was synthesized by purification and sodium-modification of a raw Ca-bentonite source (Liaoning, China) by tri-roller grinder. Important influencing factor rolling times in purification and sodium modification process was investigated. Mineral compositions, microscopic morphology, and thermal stability were characterized by using different techniques. The crystalline phases and compositions were identified by X-ray powder diffraction (XRD). The morphology and structure were evaluated by scanning electron microscopy (SEM). The thermal properties were investigated using differential thermal gravity analysis (DTG) and differential thermal analysis (DTA) analysis.

Abstract: For a refractory oxidised copper ores in Sichuan province, studing the different collectors on the influence of oxidised copper ores sulfide flotation behavior. The results showed that: the collecting performance of sodium isoamylxanthate was better. When the dosage of sodium isoamylxanthate was 550g/t, the copper concentrate grade of 19.09% could be obtained and recovery was 82.65% under the appropriate process conditions in the closed circuit experiment.

Abstract: In this study, the effect of leaching of malachite was investigated using phosphoric acid solution as leaching agent. The effect of temperature on the leaching of malachite was investigated. The leaching rate increased with increasing solution temperature, and a kinetic model was developed to represent this relationship. The leaching was controlled by the shrinking core model for surface chemical reaction. The activation energy of the leaching process was determined to be 30.65kJ/mol.

Abstract: This paper studied the influence of pH, temperature and particle size on the chemical leaching of chalcopyrite. The results show that H⁺ is not only responsible for the hydrolysis and precipitation of ferric ion as jarosite, but also related directly to chalcopyrite dissolution. The mechanism of chalcopyrite leaching is as follows: the first stage is H⁺ attacking valence band and electron transition during oxidation, which needs a great deal of the energy to the system. The second stage is the transport of electrons from the chalcopyrite surface to the dissolved oxygen. However, the limiting step changes into diffusion control from chemical control when the elemental sulphur film formed, which obstructs transport of electrons.

Abstract: Salt lakes with large reserves of mineral resources are widely distributed in China. In addition to aboundant inorganic substances, there also exist a mass of organic compounds in the brine. It is realized these organic compounds can produce serious negative effects on the process equipment and products quality. In this work, the decolorization and COD removal of the brine by ozonation were investigated in a bubble column reactor. The effects of contact time, ozone-air flow rate, pH and temperature on the decolorization and COD removal were investigated. It was found that the decolorization and COD removal rates increased with increasing ozone-air flow rate and contact time, while increased first and then decreased with increasing temperature and pH. Under the optimal conditions, color removal reached 47.3% and COD was reduced by 42.2%. Thus, ozonation can be used as the pretreatment method for decolorization and COD removal of the brine.

Abstract: Weathered phosphate ore is an important part of phosphate ore resources, it contains a huge reserves of this resources in Yunnan regions, and its reserves over 200 million tons. With the gradual consumption of the rich phosphate ore resources, recycling for weathering phosphate ore is receiving more and more people's attention. In this study, using Tian Ning weathered low magnesium phosphate ore which from Yunnan Dianchi Lake area as the study object, and based on its ore properties established a experimental program of pre-desliming with cyclone and then flotation. The P₂O₅ loss rate under 20% on the desliming operation, then using a single positive flotation process at room temperature, ultimately obtained a test indicators of phosphate concentrate of P₂O₅ grade of 29.98% and P₂O₅ recovery of 95.02%, which is a foundation of development and application for Tian Ning weathering phosphate ore.

Abstract: In order to study the electrochemical performance of coal in the HCL electrolyte system, researchers prepared the chemically modified carbon paste electrode, measured the volt-ampere curves and Tafel curves of the samples and analyzed the mechanism of the electrochemically catalysis of oxidation of coal. The studies indicate that what occurs to the coal sample in the process of electrolytic sulfur removing is a quasi-reversible diffusion controlled process. In the beginning of the sulfur removing, the rate of electrolytic corrosion is fast, in which oxidation on the anode denominates, and the cathode plays a role of reduction in the late period.