Enrichment Characteristics of Cr in Chromium Slag after Pre-Reduction and Melting/Magnetic Separation Treatment

Concentrating the chromium in chromium slag and improving the chromium–iron ratio is beneficial for the further utilization of chromium slag. In this paper, chromium slag obtained from a chromite lime-free roasting plant was used as the raw material. Pellets made of the chromium slag and pulverized coal were reduced at different pre-reduction temperatures and then separated by a melting separation process or magnetic separation process, respectively. The mass and composition of the metallized pellets before separation, along with the alloy and tail slag after separation, were comprehensively analyzed. The experimental results showed that the output yield of alloy, iron recovery rate, and chromium content in the alloy were all higher when using melting separation than when using magnetic separation, because of the further reduction during the melting stage. More importantly, a relatively low pre-reduction temperature and selection of magnetic separation process were found to be more beneficial for chromium enrichment in slag; the highest chromium–iron ratio in tail slag can reach 2.88.

Features of the internal structure of high-pressure metal-diamond composites

In the present work, composites were obtained by sintering a metal-diamond charge at a pressure of 4 GPa and a temperature of 1300°C. the experiments were carried out on a high-pressure apparatus of the split sphere “bars” type. Synthetic microcrystals of industrial synthesis were used as a diamond. The initial metal component for the experiments was copper and iron. it was shown that when sintering at high pressure, diamond crystals are tightly packed in the composite, while the metal phase completely fills the intergranular space, acting as a matrix. chemical analysis of the metal component of the samples revealed the presence of the following phases: copper-iron alloy, iron oxide and iron carbide. the results obtained indicate that several processes occur simultaneously in the diamond-copper-iron-oxygen system at high pressures and temperatures, which can significantly affect the characteristics of the resulting composite as a whole.

The Theoretical and Experimental Study on Making Low Iron Alloy from the Mixed Slag of Jinchuan Flash Smelting Furnace and JISCO Converter

Jinchuan nickel-copper flash smelting slag is rich in iron, nickel, cobalt and copper, and JISCO converter slag is rich in iron, manganese and high CaO, etc., the two kind slags were blended, and then smelted into low-alloy iron containing nickel, cobalt, copper and manganese with smelting reduction method, which is a new comprehensive utilization methods for the Double slag. The thermodynamic calculation results of the equilibrium concentration of Fe, Cu and Ni in low-alloy iron obtained by smelting reduction under experimental condition are in good agreement with experimental results. Iron reduction rate of Fe, Cu and Ni can be elevated to above 90% by smelting reduction, thus the comprehensive utilization of valuable metals can come true.

Study on the Magnetic Separation Experiment of Vanadium and Titanium Iron Concentrate Pellets

Based on Vanadium and Titanium iron concentrate pellets as raw material produced by direct reduction process of coal rotary hearth furnace in an enterprise, the paper studies the impact of magnetic separation process parameters on magnetic separation effect. The results shows that: the use of magnetic separation process can successfully separate metallized pellets, and obtain vanadium titanium micro-alloy iron powder and ti-enriched slag; suitable magnetic separation process parameters are: excitation current of 4A (magnetic field strength 2250Oe), particle size -200 mesh (-74μm), mine concentration of 1:3, iron recovery 92.5% TiO2 recovery up to 55.5%.