H3BO3–NaCl–MgCl2–H2O体系相平衡及工艺分析

测定了25, 100℃下H3BO3–NaCl–MgCl2–H2O体系的溶解度数据，并依据绘制的相图对我国西藏含钠镁的硼矿资源采用盐酸分解法制备硼酸的生产工艺进行了讨论.     

Determination of Optimal Conditions for Retention of Sulfur Dioxide by Waste Ulexite Ore in an Aqueous Medium

The main aim of this study was to remove sulfur dioxide (SO₂), which is one of the most significant air pollutants emitted from thermal power stations, using waste ulexite ore, which cannot be recycled industrially and poses a risk for the environment. In experiments conducted at atmospheric pressure in an aqueous environment, the optimization of holding SO₂ with waste ulexite ore has been investigated comprehensively and determined how much SO₂ could be retained in solid waste. The Taguchi method was used to determine the optimal conditions, and the effectiveness of the parameters was identified by variance analysis. The selected parameters and their ranges were defined as temperature (293–333?K), solid to liquid ratio (0.4–0.6?g?mL^?1), particle size (150–600?µm), time (10–30?min), pH (5.5–7.5), and stirring speed (350–800?rpm). The optimal conditions for these parameters were determined to be 333?K, 0.45?g?mL^?1, ?250?µm, 15?min, pH 6, and 350?rpm, respectively. Among all the parameters, temperature and pH were found to be the most effective. The results of the study revealed that SO₂ can be retained in solid waste with calcium content of the boron minerals as CaSO₃?·?0.5H₂O and nearly whole B₂O₃ in the waste ulexite passes into solution. Under the optimum conditions, 86% of B₂O₃ passed into the solution and 75.2?L SO₂ was retained by 1?kg waste ulexite ore. Thus, both B₂O₃ recovery and SO₂ removal were materialized, while waste ulexite ore was evaluated and removed, simultaneously.     

Investigation of sodium borohydride production process: “Ulexite mineral as a boron source”

Currently, the energy requirements of the entire world are mostly provided by hydrocarbon-based fossil fuels, such as coal, fuel oil, or natural gas. Because of environmental pollution, decrease in energy sources, and difficulties in storing electricity, more attention is dedicated to new sources of energy, such as hydrogen. Presently, sodium borohydride (NaBH₄) appears to be an excellent hydrogen-storage medium due to its high theoretical hydrogen yield by weight, 10.6%. The main aim of the present study is to investigate NaBH₄ production from ulexite mineral (NaCaB₅O₉·8H₂O). The experimental investigation consists of four steps, such as (1) Characterization of NaCaB₅O₉·8H₂O by X-ray diffraction, differential thermal and thermogravimetric analysis, scanning electron microscopy, and attenuated total reflectance of Fourier-transform infrared spectroscopy; (2) Preparation of ulexite–borosilicate glass (NaCaB₅O₉·SiO₂); (3) Synthesis of NaBH₄ from ulexite–borosilicate glass; and (4) Separation of NaBH₄ from the reaction mixture. NaBH₄ can thus be produced by heating ulexite mineral form of borosilicate glass with metallic sodium under 3-atm. hydrogen pressure at 450–500 °C for 4 h.