中文摘要：

研究了黑钨矿与碳酸钙煅烧合成白钨的反应过程和机理。实验结果表明：在550℃下煅烧黑钨矿时开始出现白钨相；在800℃下黑钨矿与碳酸钙能完全合成为白钨，主要产物为CaWO4、Fe2O3、Mn2O3。在有空气存在的条件下合成白钨的反应分两步进行：第一步生成CaWO4、FeO、MnO，第二步FeO、MnO氧化生成Fe2O3、Mn2O3。

英文摘要：

The reaction process and mechanism were studied of scheelite synthesis by calcination of wolf- ramite and calcium carbonate. The experimental results show that scheelite begins to form during wolframite calcination at 550 ℃. Wolframite and calcium carbonate can be completely synthesized into scheelite at 800 ℃, and the main products are CaWO4, Fe2O3 and Mn2 O3. Scheelite synthesis reaction in air takes place by two steps. The first step is generation of CaWO4, FeO and MnO, and the second step is oxidization of FeO and MnO into Fe2O3 and Mn2O3.