The lack of low-cost phosphorus fertilizers is a major limitation for food production on Zimbabwe’s many smallholdings. A thermally fused magnesium phosphate could be manufactured from the local Dorowa phosphate rock (PR) but would be expensive because of the high cost of required additives and energy. This paper investigates the phosphorus solubility of mixtures of igneous Dorowa PR with either recycled glass or magnesium silicates, before and after thermal alteration at sub-fusion temperatures. The thermal behavior and chemical transformation of Dorowa PR and various additives were investigated by thermo-gravimetric and differential scanning calorimetric analysis and X-ray powder diffraction. Thermal transformation of Dorowa PR + serpentine and Dorowa PR + dunite mixtures resulted in decomposition of calcite, kellyite, lizardite, and chrysotile present in the original mixtures and recrystallization of dehydroxylated metachrysotile to forsterite. The final products of air-cooled Dorowa PR + glass mixtures sintered at 1173 K contained ahrensite (Fe₂(SiO₄)), wollastonite (CaSiO₃), quartz (SiO₂), and hydroxy-fluorapatite. Compared to the unamended Dorowa PR, thermal alteration of Dorowa PR + glass mixtures at 1173 K led to a 62%, 73%, and 44% increase in citric soluble phosphorus when mixed at 1:2, 1:1, and 2:1 (Dorowa PR:glass), respectively. This increase in the citric soluble phosphorus content increases the agronomic value of Dorowa PR and is likely the result of substitution of PO³⁻₄ in hydroxy-fluorapatite by SiO⁴⁻₄ and or Mg²⁺/Na⁺ for Ca²⁺ and Fe²⁺.

缺乏低成本磷肥是津巴布韦许多小农户粮食生产的主要限制。可以从当地的Dorowa磷酸盐岩（PR）生产热熔磷酸镁，但由于所需添加剂和能源的高昂成本，其价格昂贵。本文研究了亚熔融温度下热变质前后火成的Dorowa PR与回收的玻璃或硅酸镁混合物的磷溶解度。通过热重和差示扫描量热分析以及X射线粉末衍射研究了Dorowa PR和各种添加剂的热行为和化学转化。Dorowa PR +蛇纹石和Dorowa PR +榴辉石混合物的热转化导致方解石，方解石，蜥蜴石，和温石棉存在于原始混合物中，脱羟基偏温石棉重结晶为镁橄榄石。在1173 K烧结的风冷Dorowa PR +玻璃混合物的最终产品中含有阿仑石（Fe₂（SiO ₄）），硅灰石（CaSiO ₃），石英（SiO ₂）和羟基氟磷灰石。与未经修改的Dorowa PR相比，在1173 K下对Dorowa PR +玻璃混合物进行热改变会使柠檬酸可溶性磷在1：2、1：1和2：1混合下分别增加62％，73％和44％ （Dorowa PR：玻璃杯）。这种增加柠檬酸可溶性磷含量增加Dorowa PR的农业价值，并有可能PO的替换的结果^3- ₄ 中羟基磷灰石的SiO ^4- ₄ 和或Mg ²⁺ /钠⁺为CA ²⁺和Fe ²⁺。