公开(公告)号：US5171547A

公开(公告)日：1992-12-15

申请号：US585648

申请日：1990-09-19

申请人： Ranko Crnojevich ,  Andrew B. Case ,  Felix D. Rando ,  John D. Sweeney

发明人： Ranko Crnojevich ,  Andrew B. Case ,  Felix D. Rando ,  John D. Sweeney

IPC分类号： C22B34/32

CPC分类号： C22B34/32 ,  Y02P10/234 ,  Y10S423/02

摘要： The present invention is directed to a method for treating a sludge containing substantial amounts of chromium, aluminum, calcium, iron, and phosphorous. The method comprises forming a slurry of the sludge; reacting the slurry with an acid to dissolve substantially all the aluminum and chromium and provide a solids residue comprising mostly calcium sulfate; separating the chromium/aluminum-containing solution from the solids residue; raising the pH of the chromium/aluminum solution to precipitate chromium as chromium hydroxide; and separating the chromium hydroxide from the remaining aluminum-containing solution. The chromium hydroxide is then enriched with an alkali or earth alkali compound and calcined in an oxidizing atmosphere to convert the chromium to a chromate. The calcine is leached in an aqueous medium at a controlled pH to yield a high concentration, high purity chromate solution suitable for producing metallic chromium or a variety of chromium chemicals.

摘要翻译： 本发明涉及一种处理含有大量铬，铝，钙，铁和磷的污泥的方法。 该方法包括形成淤泥浆; 使所述浆料与酸反应以基本上溶解所有的铝和铬，并提供主要包含硫酸钙的固体残余物; 从固体残渣中分离含铬/铝的溶液; 提高铬/铝溶液的pH以使铬沉淀为氢氧化铬; 并将氢氧化铬与剩余的含铝溶液分离。 然后将氢氧化铬用碱或碱土碱化合物富集，并在氧化气氛中煅烧，将铬转化为铬酸盐。 将煅烧物在受控pH下在水性介质中浸出，得到适用于生产金属铬或各种铬化学品的高浓度，高纯度铬酸盐溶液。