Advanced Materials Research Vols. 652-654

Abstract: The main problem with the efficient utilization of Nb resource in the Boyan Obo Ore lies in the selective oxidation of [Nb], [P] and [C]. In this work, thermodynamic studies have been conducted to determine the conditions of selective oxidation of [Nb], [P] and [C] in low niobium hot metal in the process of oxidizing dephosphorization. The thermodynamic condition for dephosphorization was determined as: The condition for retaining Nb from oxidation is: The oxygen activity for oxidation of Nb, C and P is relevant to the initial [C] content in hot metal. The equilibrium oxygen activity of Nb-O reaction increases with an increase of the [C] content, whereas the equilibrium oxygen activity of C-O and P-O reactions varies oppositely with the [C] content. The reduction ofresults in a decrease of the [C] content required for removing P and retaining Nb, as well as makes the process of dephosphorization more feasible. The increase of temperature decreases the [C] content of selective oxidation of Nb and P, but is unfavorable to dephosphorization.

Abstract: The structure and composition of carbon materials affect obviously the result of carbothermic reduction of magnesia. Coke, charcoal and graphite were used in reduction experiments under the same conditions. The reactivity ratio of magnesia and XRD pattern of residues were analyzed and compared. The reactivity ratio of magnesia by coke was similar to the one by charcoal. The amorphous carbon in coke graphitized partly in reduction experiments of 1673K. The results show that the effective composition in coke is the amorphous carbon. It also suggests that the temperature of reaction should be control less than 1700K to avoid the amorphous carbon’s graphitization.

Abstract: The research to increase injecting amount into blast furnace was carried out on the basis of the actual production of Longmen Steel Co., Ltd.. This paper starts with the study of pulverized coal properties of the blast furnace, combined with the experimental researches such as explosibility study of pulverized coal, the study of the effect of adding additives on combustion properties of Pulverized Coal, the factors affecting the amount of injection coal of Blast Furnace in Longmen Steel Co., Ltd. were identified and the specific measures to improve coal ratio and reduce the coke ratio were put forward by theoretical analysis and experimental research as well as practical production.

Abstract: The Middle Cambrian Tianpeng Formation volcanic rock, which was found in Baishiyan area in Wenshan recently, is the typical basalt. Through the research of Tianpeng Formation Sedimentary Enviroment and analysis of the geochemistry which includes the major elements, REE and Trace Element in the volcanic rock, SiO2 is 45.78-54.88%, total alkali (alk)=1.22-4.97 and K2O/Na2O=0.03-0.53, we can say that it should be tholeiite series. ∑REE=48.60-157.11ppm,LREE/HREE7.56-9.48,δEu0.40-1.05.REE distribution patterns show oblique to the HREE side and enrichment in LREE , the Eu anomaly is not obvious. We can see from the Trace Element Correlogram that the volcanic in this area is formed from the intiaplate basalt environment. The Tianpeng Formation in this area is clastic rock in a shallow sea and a basin facies and also is the deposit of flysch-simiflyschoid of siliceous and carbonate rock. Also, it deposit with the some undercompensation basin like laminated striation structure. All of those reflect that the structure background of the Middle Cambrian in Wenshan area has strong tensive back-arc spreading.

Abstract: he existence of oil-water transition layer brings a great trouble to the dehydration of oil gathering and transportation system. It leads to raising the electric current of dehydrator and becoming worse of the deoiling and dehydrating properties of the treatment equipment, resulting in the serious influences on oil recovery. For the efficient treatment of the transition layer, it is necessary clearly to understand the structure and composition of the layer. In this paper, the physical structure and chemical composition of the layer were systematically, layer by layer and phase by phase, analyzed by modern instrumental methods The results show that (1）the layer is an emulsion which is composed of oil, water and suspended solids. The water phase has characteristics of weak alkaline，high salinity and viscous polymer. The oil phase contains many natural emulsifiers such as colloid, asphaltene and so on. The solid phase mainly concludes FeS particle which plays a decisive role in suspended solids; (2) the typical transition layer is composed of water and oil which accounts for above 90%, the content of solid impurity, which controls the emulsion of the layer, is less than 10%. Compared with oil phase, the water content of typical transition layer is larger with the density of 0.9~1.0 g/L and high freezing point. The analytical data can be adopted for the treatment of oil-water transition layer and smoothly run operations for oil gathering and transportation.

Abstract: High-alumina fly ash in central and western regions of Inner Mongolia is a very valuable renewable mineral resource resulting from the content of Al2O3 up to 50% and some available elements, such as gallium, titanium and light rare earth. According to the resource characteristics of high-alumina fly ash and the market demand of the non-ferrous metals and chemical products in national economic development, a technique route was researched and developed, which included high-alumina fly ash as the main raw material, extraction of alumina co-generated with active calcium silicate (chemical packing) and calcium silicon slag cement clinker. It is the process characteristics that according to the development concept about circular economy, making full use of fly ash and recycling water as sewage disposal from thermal power plants, calcium carbide slag from chemical plants and other disused resources, and achieving the separation of alumina and silica and their respective resource utilization.

Abstract: Grade of fluorite in this test is 30.95%,containing CaCO3 0.86%. On the base of much experiment research, such as grinding fineness test, pH test, agent dosage test and so on, the optimum conditions were: grinding fineness for first stage is -0.074mm 65%,pH=9, sodium silicate 0.8 kg/t and oleic acid 0.7 kg/t . The result of tests showed that the grade of CaF2 concentrate, recovery and productivity are 95.38%, 63.42% and31.20% by adopting a circuit of one rough flotation and seven concentrating with grinding fineness -0.043mm90.3%.

Abstract: The thermal decomposition kinetics of magnesite and limestone, which are alkaline earth metal carbonates, were investigated using thermal analysis method. The research results showed that their kinetic decomposition characteristics and apparent decomposition activation energy have the comparability. Based on the thermodynamic/thermogravimetric data, the industrial production process of magnesite and limestone can draw on the experience of each other because of their similar decomposition thermodynamics and kinetics.

Abstract: On the basis of study on the ore property of magnetic ores containing apatite,The experiment results show that a magnetic concentrate having a recovery of 58.04%,a concentrate containing 60.38%Fe and yield of 10.90% after by means of two-stages magnetic separation at a grinding fineness of 75%-200 mesh of the first stage , grinding fineness of 85%-200 mesh of the second stage After the first magnetic separation. Based conditional experiment and open-circuit test, under a grinding fineness of 50%-200 mesh, through a flotation flowsheet of "one-stage rough flotation, three-stage cleaning and one-stage cleaning" with the first magnetotail ,a apatite concentrate with P2O5 33% , The yield of apatite was 10.90% , the recovery of apatite reaches to 85% and can be obtained in which the total iron content is lower than 2%.