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At present, the production of magnesium is mainly carried out semi-continuously with ferrosilicon as reducing agent under high temperature and high vacuum. In order to continuously produce magnesium, a new method of extracting magnesium from low-grade magnesite and calcium carbonate by silicothermal method in flowing inert gas was proposed. The effects of calcium fluoride (CaF2) on decomposition rate, decomposition kinetics, reduction rate of magnesia, and crystal type of dicalcium silicate in reduction slag were investigated in the paper. The experimental results showed that calcium fluoride could accelerate the decomposition of carbonate, and had no side effect on the calcined products. In addition, the analysis results of DTA curves showed that calcium fluoride could reduce the decomposition reaction activation energy and the reaction temperature of carbonate in the prefabricated pellets. The results of reduction experiments showed that proper calcium fluoride could promote the reduction rate of magnesia, and in the temperature range of 1250? ~ 1350?, with the same timeframe, the corresponding calcium fluoride contents were 5%, 3%, and 1% respectively when the reduction rate reached the maximum. Excessive calcium fluoride reduced the reduction rate of magnesia, but it promoted the transformation of dicalcium silicate to ? phase in the reduction slag.

The condensation behavior of magnesium vapor in argon was studied. Thermodynamic analysis showed that magnesium vapor condensation was controlled by partial pressure and temperature and that temperature was the main factor affecting condensation. When the actual magnesium vapor partial pressure was 371.2 Pa, the magnesium vapor changed from gas to liquid and then to solid. Experimental results showed that droplet magnesium with particle sizes of 0.15 to 1.04 mm, transitional condensed magnesium with particle sizes of 2 to 25 μm and powdered magnesium with particle sizes of 0.5 to 8 μm were obtained at 1000 °C and 0.2 m3/h. This phenomenon occurred as the temperature in the constant temperature zone increased from 1000 °C to 1200 °C. The initial temperature of the droplet condensation zone increased from 618 °C to 776 °C; the initial temperature of transitional condensation zone was 492 °C to 552 °C and the initial temperature of the powder condensation zone 420 °C to 458 °C. When the argon flow rate increased from 0.1 to 0.4 m3/h, droplet magnesium decreased from 52.68 to 11.32 pct and the powder magnesium increased from 24.06 to 57.98 pct. Controlling the temperature and gas flow, different magnesium crystalline microstructures were obtained, which provided a means for magnesium vapor condensation in a continuous magnesium extraction process.

Metal magnesium is mainly produced from the calcined dolomite by the vacuum silicothermic process. However, it requires a high energy input. An improved process was proposed in which the magnesium was produced from pre-prepared pellets. In this work, diffusion and phase transformations in the pre-prepared pellets during the reduction process were investigated. The results suggested that the reduction ratio is remarkably increased as the reduction temperature increased or the dolomite/ferrosilicon molar ratio decreased. Only Si diffused into dolime, which caused the reduction reactions and Fe might not have been involved in the reactions. The liquid Ca-Si alloy was produced. CaSi was an important intermediate product to produce CaSi2 and Ca vapor. Both CaSi2 and Ca vapor were the effective reducing agents for MgO. This process for Mg production includes both solid–liquid and solid–gas reactions. A plausible reactions route was proposed based on experimental and thermodynamic analyses.

The Pidgeon process is the main extraction method of magnesium, but its continuous production cannot be achieved due to the switch between vacuum and atmospheric pressure. Therefore, it is vital to realize continuous extraction of magnesium under atmospheric pressure. In this paper, the process of extracting magnesium from prefabricated pellets in flowing argon was proposed. The isothermal kinetic analysis of the reduction process was carried out. The results showed that the reduction process was controlled by diffusion process in 1 h, and the apparent activation energy of extracting magnesium from prefabricated pellets in flowing argon was 218.75 kJ/mol. Then the influence of experimental factors on the reduction rate was explored, including briquetting pressure, carrier gas flow rate, ferrosilicon content, reaction temperature and time. Through analysis and calculation, it was concluded that the main control step of diffusion process was silicon diffusion.

Carbide slag is a kind of industrial waste produced from the calcium carbide industry, which is difficult to treat and cannot be used reasonably. In this paper, carbide slag as a calcium source for extracting magnesium was proposed, i.e., carbide slag was directly mixed with low-grade magnesite instead of dolomite as raw material for extracting magnesium without pretreatment. The process is simple to operate and can obtain metal magnesium while reducing nearly 50% of CO2 emissions in the process of extracting magnesium. In the work, the strength of pellets, the effects of Ca/Mg ratio, and calcination temperature on the recovery rate of Mg were investigated. The results showed that low temperature calcination was beneficial to reduction and the recovery rate of Mg increased with the increase of Ca/Mg ratio, and the reduction rate was 87.95% when the Ca/Mg ratio was 1.2.

The condensation behavior of magnesium vapor produced by metal Mg or pellets for magnesium production is investigated at heat source temperatures of 1173–1473 K under vacuum. The possibility of reduction of magnesite in vacuum was analyzed by means of thermodynamics. The results indicate that the thermal motion of magnesium is violent, and the volatilization rate increased with high heat source temperature, the results accord with Maxwell's velocity distribution law. Magnesium vapor condensation products were obtained with flake and powder macromorphologies, where the flake products accounted for more than 80% (in mass). Scanning electron microscopic analysis revealed that the main factor affecting the magnesium vapor condensed particles was the vapor pressure, which was determined by temperature and reaction. The end condensation temperature was between 528.1 and 637.1 K when the heat source temperature was 1173–1473 K. Increasing the temperature gradient decreases the condensation temperature range. X-ray diffraction results showed that the magnesium condensation products were more crystalline at lower vapor pressure and a small temperature gradient. The presence of Ca2SiO4 in the reduction slag indicated the occurrence of the reduction reaction. The experimental results from pellets for magnesium production were consistent with those involving Mg metal.

Studies were performed in 20 patients with breast cancer, who received 26 cycles of high-dose cisplatin (100 mg/m2, IV. drip). In twenty-five cycles of them urinary Alb, IgG and NAG showed abnormal values. The patients were divided into low-nephrotoxicity and high-nephrotoxicity groups by the degree of renal dysfunction. Thirty-five percent of the patients exhibited high-nephrotoxicity. These patients had significantly higher plasma and/or urinary Pt peak levels during cisplatin (CP) infusion than did low-nephrotoxicity. 70–80% of the patients developed significant nephrotoxicity when urinary Pt peak level rose up to 40 μg/ml or plasma Pt peak level >4 μg/ml. It is quite important to reduce nephrotoxicity that urinary Pt level is controlled below 40 μg/ml and plasma Pt level 100 ml/hr during 3 days after the infusion. That may keep the nephrotoxicity of CP in less serious degree and easy to recover.