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研究了用低品位锡矿（含锡２０％～３０％）直接制取锡酸钠的工艺流程，即把锡矿先进行还原焙烧，然后用ＮａＯＨ溶液浸出，最后把溶液浓缩结晶制成锡酸钠产品．试验表明，焙烧温度９００℃，煤粉和锡矿的质量比为１．０２．５，焙烧时间１．５ｈ，焙砂浸出时碱液的浓度为ＮａＯＨ５ｍｏｌ／Ｌ和ＮａＮＯ３０．３７６ｍｏｌ／Ｌ，液固比为５１（质量比），浸出温度９５～１００℃，浸出时间４ｈ，是较好的条件，锡浸出率达到了９３％～９４％．浸出液经过浓缩结晶，产出的锡酸钠质量高于广州Ｑ／ＨＧＩ５８－８４企业标准．全流程５次循环试验表明，杂质在浸出液中的积累极为缓慢，浸出液仍可不经化学净化直接进行浓缩结晶
In this paper, the technological process of preparing sodium stannate directly from low-grade tin ore (containing 20% -30% tin) was studied. The tin ore was reduced and roasted first and then leached with NaOH solution. Finally, the solution was concentrated and crystallized to form stannic acid Sodium product. The results showed that the calcination temperature was 900 ℃, the mass ratio of pulverized coal and tin ore was 1.02.5, the calcination time was 1.5h, the concentration of lye was 5mol / L NaOH and 30.376mol / L NaNO3 when calcine leaching, Ratio of 51 (mass ratio), the leaching temperature of 95 ~ 100 ℃, leaching time 4h, is a better condition, the leaching rate of tin reached 93% ~ 94%. Leaching solution after crystallization, the output of sodium stannate quality higher than the Guangzhou Q / HGI58-84 corporate standards. The whole process of 5 cycles showed that the accumulation of impurities in the leachate is very slow, the leachate can still be directly concentrated and crystallized without chemical purification