Wan Zhong Yin

Toughening of Polypropylene with Calcium Sulfate Whiskers Treated by Coupling Agents

Calcium sulfate whiskers are modified by three kinds of coupling agents. The modified calcium sulfate whiskers are then introduced into polypropylene to prepare calcium sulfate whiskers/PP composites. Mechanical strength tests show that notched izod impact of polypropylene increases dramatically by adding calcium sulfate whiskers. When a silicane coupling agent KH-570 is adopted to modify calcium sulfate whiskers at 30 % (w/w) of whiskers, the notched izod impact of composites can increase by nearly 60 %. SEM is utilized to observe the impact fracture surface morphology of the composites and the distribution of calcium sulfate whiskers in the PP matrix. The results indicate that the surface treatment can promote uniform distribution of calcium sulfate whiskers in the PP matrix, and improve the notched izod impact and toughness of composites. Coupling agents play a role in toughening for the calcium sulfate whiskers/PP composites.

Synthesis of Hydrotalcite Using Brucite as the Source of Magnesium

The hydrotalcite was synthesized using brucite as the source of magnesium by the method of coprecipitation. The effect of synthesis parameters, such as Mg2+ concentration of solution, crystallizing time and temperature on their crystal structure were studied. The surface morphology was characterized by SEM, and the structure was characterized by XRD. Characterization of hydrotalcite showed that the particle size of the hydrotalcite with high degree of crystallinity was 10.0～0.1μm, and the Mg2+ concentration of solution, crystallizing time and temperature influenced the crystal structure. The proper Mg2+ concentration was 0.12M, and the optimal crystallizing time and temperature were 8h and 80°C, respectively.

New Flotation Technology Research on Carbonate-Containing Hematite

A new flotation technology of carbonate-containing hematite was introduced in this paper, The results show that iron minerals are mainly composed of hematite, siderite, magnetite, limonite, ankerite, quartz, hornblende, and a small amount of chlorite, etc. The increase of iron carbonate can deteriorate the normal flotation of hematite, but now a new flotation technology can weaken the negative influence of iron carbonate on flotation, by which we can obtain the iron concentrate with grade of Fe 66.26 %, recovery of Fe 70.23%. It has been comprehensively demonstrated that the dispersant plays an important role in the selective separation of hematite from iron carbonate and iron silicate.

Effect of Siderite on Reverse Flotation of Dong Anshan Iron Ore Containing Carbonates

The content of carbonate minerals in Dong Anshan iron ore was increasing in recent years, which deteriorated reverse flotation indices or even resulted in unclear separation between concentrate and tailing. In dodecylamine and sodium oleate systems, reverse flotation tests were undertaken with artificial mixed minerals of martite, quartz and siderite. Based on mineral flotation tests, the effect mechanism of siderite on reverse flotation were investigated in terms of SEM and EDS. Results showed that siderite was weakly depressed by starch, and the adsorption of siderite on hematite and quartz was the main cause for reverse flotation difficulties. In reverse flotation in dodecylamine system, the adverse effect of siderite on reverse flotation could be reduced when the amount of starch increased, and iron minerals and quartz were separated effectively. Therefore, the reverse flotation in dodecylamine system could be considered to realize separating effectively iron minerals and quartz of Donganshan iron ore containing carbonates, but which had high requirements on pH. Other methods were siderite being separated prior to reverse flotation or inventing flotation agents capable of effectively activating or depressing siderite.

Flotation and Purification Research on Low Grade Magnesite in Kuandian of Liaoning

Low grade magnesite coexisting with dolomite was purified by flotation. A process of reverse flotation to remove silicate minerals- positive flotation to concentrate magnesite was explored after the systematic process mineralogical investigation. Influence of different conditions such as grinding fineness experiment, collector experiment and combined modifiers experiment was also investigated. Open-circuit flotation test was carried out under the optimum conditions. It was showed in the result that the MgO content in concentrate was increased from 32.36% to 42.25%, the CaO and SiO2 contents in concentrate were decreased from1.08% and 17.70% to 6.73% and 0.19% respectively, but the recovery of MgO was not satisfactory.

Flotation Research on Dolomite-Containing Magnesite Ore

China has the largest magnesite reserve in the world. However, the high-grade magnesite resources are decreasing significantly with the development of the resources’ consumption. The treatment of the low-grade magnesite ore is becoming more important and of much interest to researchers. In this paper, the floatability of several pure minerals including magnesite, dolomite, and quartz and their interactions when using different collectors were investigated. In the flotation system of lauryl amine, compared with magnesite, the floatability of dolomite was higher, but was much lower than quartz. In the flotation system of sodium oleate, magnesite and dolomite had good floatability but quartz could hardly be floated. Sodium hexametaphosphate inhibited dolomite more strongly than magnesite. When pH was above 9, the inhibitory effect on two minerals was attenuated, and in the pH range of 9~12, the inhibitory effect of sodium silicate on dolomite was very strong, while magnesite still had good floatability. Magnesite and dolomite crystal structure similar and the mass contents of surface oxygen were respectively 52.42, 48.65. relative density that was the ratio of metal cation to anion （∑Mn+/∑O2-）, respectively: 0.3264,0.4327. The mass contents of surface oxygen and relative density affected the surface electric properties, and therefore the isoelectric point of dolomite was higher in solution.Based on crystal chemistry formulas, the Mn+-O2- bond parameters were calculated. The electronegativity of O linked with Ca in dolomite was much higher than that linked with Mg in magnesite and dolomite. Because of the strong electrostatic forces, the floatability of dolomite was higher in the flotation system of lauryl amine. As the solubility product of calcium oleate is bigger, the floatability of dolomite which compared to magnesite is much higher in the flotation system of sodium oleate. After the flotation experiments of pure minerals, a novel flotation system for recovering magnesite concentrate from low-grade magnesite ore was developed. For run-of-mine ore produced in Liaoning China, the results of flotation experiments showed that a magnesite concentrate containing 46.94 percent MgO, 0.30 percent SiO2, 0.76 percent CaO can be produced and 76.02 percent of the magnesite can be recovered through the process.

Separation Tests of Low-Grade Gold Ore with High Sulfur and Arsenic

With the rise of gold prices, a large amount of gold resources will be exploited, which leads to more and more refractory gold ore appeared. It has very important practical significance to accelerate the development of refractory gold resources. This paper has done the separation tests of low-grade gold ore with high sulfur and arsenic from Tianmashan, Tong Ling in China. The chemical elements component, mineral composition, and the dissemination of mineral and gold have been analyzed. The separation flowsheet tests have been explored, and the preliminary results and appropriate reagent regime have been obtained.

Separation Test of Andalusite Ore Containing Carbon from Fengcheng City Liaoning

The paper studied on andalusite ore containing 6.58% carbon from FengCheng, Liaoning province for mineral processing. The study on the technical mineralogy of the ore showed that the main mineral were andalusite, biotite and quartz. The well results were obtained by adopting grinding-desliming-decarburization-flotation-magnetic separation and using sodium petroleum sulfonate as collecter. The mechanism of flotation reagents was analyzed in the end of the paper.

Flotabilities of Iron Minerals and Quartz in Flotation System of Dodecylamine

During practical production, siderite has an influence on flotation efficiency to hematite and magnetite. In flotation system of dodecylamine, this paper studied the flotation properties of single minerals such as magnetite, martite and quartz firstly. On this basis, the influence of siderite to flotation efficiency of martite-quartz and magnetite-quartz mixed ores was discussed. The result shows that siderite will seriously effect on the flotation efficiency of hematite (magnetite)-quartz mixed ores. Increasing the amount of starch will weaken the impact of siderite to some extent.

Research on Process Mineralogy of Potassium-Rich Shale

The process mineralogy of potassium-rich shale from Chaoyang of Liaoning, China, was studied. Research results showed there are much less variety and smaller quantities in mineral compositions. Calculated mineral composition by means of chemical composition analysis combined with XRD, MLA, IR and TG-DSC analyses showed that main minerals with were Potassium-feldspar, muscovite, biotite and illite, and gangue minerals were quartz and small amounts of hematite. Potassium-rich minerals such as potassium-feldspar and muscovite contact smoothly with quartz respectively, and there was the direction arrangement among potassium-feldspar, quartz and muscovite in the shale. And quartz and hematite were main cement in the shale. The influences of the research results on the potassium extraction from potassium-rich shale were distinct.