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In order to achieve highly efficient utilization of three valuable elements Fe, Ti and V simultaneously from vanadium-bearing titanomagnetite ore sands, an improved carbothermic reduction method was proposed and verified in both laboratory scale and industrial test-bed scale. The method combined the process of direct reduction and the process of further reduction and separation. Particularly, pulverized coal injection was introduced. In experimental tests, the effects of parameters such as carbon content in briquette, reduction duration and reduction temperature on the contents of metallic Fe and FeO as well as Fe metallization rate were analyzed. Experimental results indicated that Fe metallization rate in the carbon-containing briquette could reach 75.83%. In the industrial test-bed tests, the effects of carbon content in briquette, reduction duration and reduction temperature were also investigated, respectively. In addition, processes with and without pulverized coal injection were tested. The comparative analysis indicated that the content of TiO2 in titaniferous slag was increased by applying pulverized coal injection, and it can reach 82.5 wt.%. Meanwhile, the energy performance analysis showed that the equivalent electricity consumption of the test-bed dropped significantly to 2071 kWh per ton of slag, about 26.0% less than that of traditional method. Moreover, the investment payback of the test-bed is 3.4 years. Both experiments and industrial test-bed tests demonstrated that the proposed method has the advantages of highly efficient utilization, high energy efficiency as well as good economic performance.

High-titanium slag is not only the substitute for the gradually depleted natural rutile resources but also the important raw material for the clean production of titanium industry. In this paper, a modeling of energy consumption evaluation for production of high-titanium slag using the ilmenite as raw material was proposed, then the energy consumption of high-titanium slag production by direct reduction-melting and separation process (two-stage process) was measured on production site. The energy consumption of high-titanium slag was converted into standard coal energy or electric energy by the energy value method and the energy equivalent method, respectively, on the base of data collected from the plant. The electric energy consumption of high-titanium slag produced by the two-stage process was 1661.6 kWh per ton slag with the energy value method. Due to the energy value conversion method more reflects the value of electricity, which is suitable for applying to the energy consumption evaluation of high-titanium slag production.

The traditional silicothermic process of magnesium metallurgy with dolomite at high temperature and under high vacuum condition results in high operation costs, discontinuous production and huge production consumption. Based on this, a new thermal reduction process of magnesium preparation is proposed with serpentine as raw material at ordinary pressure. It is shown by thermodynamic analysis that the calcined products of serpentine is the compound of 2MgO•SiO2 and MgO•SiO2. Furthermore, the thermal reduction process at ordinary pressure is determined by using calcined products of serpentine as raw material, CaC2 as reductant and CaO as additive. Comparing with traditional silicothermic process, the new process has many advantages due to higher magnesium content of serpentine, lower price of the reductant CaC2, lower reaction temperature in calcined and thermal reduction process, and ordinary pressure reaction conditions for continuous production.

In this paper, a new process of using high grade ores, such as magnesite and water magnesium stone etc, to produce magnesium is proposed from the thermodynamic point of view. For the ores, the main component of calcined products is MgO. Considering the reaction activity, price and material stability, CaC2 is chosen as the reductant in the new process. Furthermore, the optimal reaction is determined as the reduction of MgO by CaC2 adding SiO2 based on the principle of Gibbs free energy. It is found that the initial reaction temperature is 947°C under ordinary pressure showing the reaction taking place without vacuum condition. Compared with the traditional silicothermic process, the new process is not only simple but also can achieve continuous production due to the thermal reduction under ordinary pressure, as a result that it is easy to industrial application in the present technological level and conditions.