草木灰改质钢渣的溶出行为及肥效

Dissolution behavior of steelmaking slag modified by plant ash and its fertilizer efficiency

脱磷钢渣中含有SiO_(2),P_(2)O_(5),Fe_(x)O等多种有价组分,可为植物生长提供营养元素.为了提高脱磷钢渣中有价元素的溶出并促进其在农业中的应用,利用草木灰对熔融钢渣进行改质,研究了草木灰掺加量和浸出条件对元素溶出行为的影响,同时考察了改质脱磷钢渣对植物生长的作用.结果表明:脱磷钢渣中掺加质量分数为10%的草木灰时,改质钢渣中的铁由CaO-FeO-SiO_(2)系的玻璃相向RO相中富集;在相同条件下,该改质脱磷钢渣中有价元素的溶出率较高;随着pH值的降低,改质钢渣中各元素的溶出率进一步升高,当pH=5时,柠檬酸溶液中磷的溶出率最高可达80.47%,钙的溶出率最高为59.76%;柠檬酸溶液作为浸出剂时更有利于有价元素的溶出;向土壤中添加改质脱磷钢渣后,植物的长势和叶片大小均得到显著改善,改质脱磷钢渣有成为肥料的潜力.

Dephosphorization slag contains SiO_(2),P_(2)O_(5),Fe_(x)O and other valuable components,which can provide nutrient elements for plant growth.In order to improve the dissolution of valuable elements and promote its application in agriculture,the dephosphorization slag was modified by plant ash,and the effects of the percentage of plant ash and leaching conditions on the dissolution behavior of elements were studied.Moreover,the effect of its application on the growth of plants was also investigated.The results show that when 10%plant ash was added to dephosphorization slag,Fe in the modified steel slag was enriched from the CaO-FeO-SiO_(2) glass phase to RO phase.Under the same leaching conditions,the dissolution ratio of valuable elements in this modified steelmaking slag was higher compared with other slags.As pH value decreased,the dissolution ratio of each element further increased.Besides,the dissolution ratio of P in citric acid solution with pH=5 was up to 80.47%,and the dissolution ratio of Ca was up to 59.76%.Citric acid as the leaching agent was beneficial for the dissolution of elements.After adding modified steelmaking slag to the soil,plant growth and leaf size were significantly improved,which had the potential to become fertilizer.