The phase transformation characteristics of lead sulfate (PbSO₄) in a sulfuric acid (H₂SO₄) system were studied, focusing on the effects of temperature, H₂SO₄ concentration, ferric iron (Fe³⁺) concentration, sodium sulfate (Na₂SO₄), and potassium sulfate (K₂SO₄). The conversion of PbSO₄ was analyzed by characterizing the composition and structure of the solid product through XRD, SEM/BSE-EDS, and FT-IR. The results indicated that the effect of temperature on PbSO₄ transformation was influenced by H₂SO₄ concentration. The temperature threshold for PbSO₄ conversion to lead jarosite (Pb-J) decreased from 150 to 90 ℃ as H₂SO₄ concentration decreased from 20 to 5 g/L. At 150 ℃, the amount of jarosite generated decreased significantly from 86.04 to 9.76 %. Subsequently, when H₂SO₄ concentration exceeded 40 g/L, PbSO₄ was essentially unchanged. Concurrently, Pb-J formation correlated with the partial formation of hydronium jarosite (H-J). The production of jarosite was inhibited when the solution pH was ∼ 0.3 or lower. Furthermore, the increase in Fe³⁺ concentration facilitated Pb-J formation, whereas Na₂SO₄ and K₂SO₄ inhibited Pb-J formation, leading to the formation of potassium jarosite (K-J) and sodium jarosite (Na-J), respectively. This study provided insights into regulating PbSO₄ conversion during sulfide ore oxygen pressure leaching.

中文翻译：

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硫酸铁介质中硫酸铅的相转化特性


研究了硫酸铅 （PbSO₄） 在硫酸 （H₂SO₄） 体系中的相变特性，重点研究了温度、H₂SO₄ 浓度、三价铁 （Fe³⁺） 浓度、硫酸钠 （Na₂SO₄） 和硫酸钾 （K₂SO₄） 的影响。通过 XRD、SEM/BSE-EDS 和 FT-IR 表征固体产物的组成和结构，分析 PbSO₄ 的转化率。结果表明，温度对 PbSO₄ 转化的影响受 H₂SO₄ 浓度的影响。当 H₂SO₄ 浓度从 20 g/L 降至 5 g/L 时，PbSO₄ 转化为黄铁矿铅 （Pb-J） 的温度阈值从 150 °C 降至 90 °C。在 150 °C 时，黄铁矿的生成量从 86.04 % 显著下降到 9.76 %。随后，当 H₂SO₄ 浓度超过 40 g/L 时，PbSO₄ 基本保持不变。同时，Pb-J 的形成与水合氢盐 （H-J） 的部分形成相关。当溶液 pH 值为 ∼ 0.3 或更低时，黄铁矿的产生受到抑制。此外，Fe³⁺ 浓度的增加促进了 Pb-J 的形成，而 Na₂SO₄ 和 K₂SO₄ 抑制了 Pb-J 的形成，分别导致黄铁矿钾 （K-J） 和黄铁矿钠 （Na-J） 的形成。本研究为硫化物矿石氧压浸出过程中调节 PbSO₄ 转化提供了见解。