In tailings selection production practice, ore dressing factory annually discharge 5 million tons tailings. Tailing grade is 7.62% before selection, and the final grade of tailings is 6.15% through selection again. Dressing workshop discharges total tailings, we select coarse fine ore from which by HS type magnetic recycling machine. Then rough fine mine will be sent to separate established of again selected factory with pump. The process is weak magnetic selection, mill mine ratings, magnetic dehydration slot, weak magnetic selection, fine sieve, weak magnetic selected, filter, and finally we obtained eventually fine mine. Secondary recovery of valuable metals from tailings is an important aspect of tailings comprehensive utilization. An important characteristic of mineral resources in China is single, less, associated raw mine. Due to poor technology, equipment and poor management systems in the past, tailings containing a variety of valuable metals and minerals, all of which have not been fully recovered. In the area of comprehensive iron construction waste crusher recovery, iron construction waste crushers generally contains iron 8%-12%. If we estimate according to the national available heap memory 4 billion tons of iron construction waste crusher, the iron abundance is still 3. 21~4. 8 billion t. If the recovery rate is 50%, we can obtain 1.61 240 million tons of iron resources. It is a considerable value; In comprehensive recovery of nonferrous metal mine tailings, the vast majority of China Nonferrous Metal Mining stone crusher machine are intergrowth type and concomitant type. The valuable metals in tailings are of useful minerals and extremely rich. Therefore, it is of great practical significance for the recovery of valuable metals and minerals in the non-ferrous metal mine tailings; In terms of gold mine tailings comprehensive recovery, most of current gold grade in the gold mine tailings is more than 0.5 g/c, some of them even as high as 45/t. At the same time the gold tailings also contains Cu, Pb, Zn, s, Fe, Ag, Sb, Wu and other valuable metallic elements, so the value of comprehensive utilization is very high. Continuous enrichment makes solid separating from liquid rely on gravity, the purpose of which is to improve the concentration of solids in slurry. The concentration of common thickener underflow is generally 30%~400/e, overflowing solid content can be achieved 10~20 grams per litre. Besides, due to the classifier large footprint, the resulting construction and installation cost is also higher. By contrast, the efficient thickener is small size, underflow concentration can be more than 70% per cent.