Processing nonferrous metal hydroxide sludge

Processing Nonferrous Metal Hydroxide Sludge Wastes... 

Muller, W. and Witzke, L., Processing Nonferrous Metal Hydroxide Sludge Wastes. U.S. patent 4,151,257. Free patent available at http //www.freepatentsonline.com/4151257.html, 2007. 

Nonferrous metal hydroxide sludge wastes contain a large quantity of water, and the content of valuable metals is too small to allow economical smelting of these wastes. However, the wastes are a burden on the environment and they can only be deposited in special garbage dumps, which are very costly. Therefore a method for processing and recovery of the valuable materials and metal in the waste is highly desirable. 

Such a method has been patented in the U.S.31 for processing the nonferrous metal hydroxide sludge wastes containing chromium, copper, zinc, and nickel for simultaneous recovery and separation of the individual nonferrous metals sequentially. In this method, the individual nonferrous metals, such as, chromium, copper, zinc, and nickel can be individually and economically separated from the collected nonferrous metal hydroxide sludge wastes. This is achieved by the combination of the following steps performed in sequence31 ... 

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