According to our understanding of the situation, the existing recycling technology mainly has several types, one is the so-called high temperature treatment method, including: saltpeter melting, air oxidation sintering, oxygen calcination method; two is the mechanical crushing method, including: cold crushing grinding, grinding, crushing heat zinc melting method; three is a chemical treatment method, including metal multivalent salt treatment, chlorination, phosphoric acid, hydrochloric acid leaching treatment method; the four is the electrochemical method, have different routes with alkali as the dielectric, with hydrochloric acid or sulfuric acid and nitric acid as the dielectric; also useful through hyperbaric oxygen, ammonia or amine solution leaching method; light based compound method and steam distillation were decomposition method and so on.

Since the advent of cemented carbide,recycling issues have been of concern to the industry. Tungsten carbide is the main raw material of tungsten carbide and rare metal, and its economic value and manufacturing cost is relatively high. In the recent years, because of the increasingly strict requirements of environmental protection, some recycling processes will be stopped due to pollution. At present, it is widely used in the field of mechanical crushing, zinc melting and selective electrochemical dissolution. For the evaluation of these processes, it is very difficult to choose a more reasonable, more economical and more worthy of popularization and application, because the quality of process route of the first and the basic principle is recycled products to be high, the process should be simple, have two times of no pollution to the environment, labor conditions should be clean and safe. This paper briefly introduces several commonly used recycling processes.

Crushing method

For hard alloy containing drilling is not high, because the hardness is relatively low, can use manual or mechanical means broken to a certain fineness in wet grinding mill for a period of time, to reach a certain size for reproduction of hard alloy. This force is a method has the advantages of simple process, short process, low energy consumption, no pollution to the environment, but often in the manual crushing hard alloy, metallic materials due to debris into the tools have broken material pollution, in addition, due to the hard alloy drill containing high amount of easily broken, mechanical crushing method is very limited; cemented carbide complex material by this method is also very difficult to ensure the quality of recycled products.

Process method: artificial crushing is broken, crushed into powder 200 mesh or using bulk of hard alloy ball mill for crushing strikes the ball, then add in the bjm alcohol in wet grinding, and then enter the remanufacturing process of hard alloy. Some companies use cooling method: first crushing waste hard alloy in a muffle furnace heated to 80 above this immediately into the water quench, resulting in hard alloy cracking, and then enter the mechanical crushing process.

At present, there is still some room for the development of crushing method, the use of more advanced cleaning equipment or the use of high efficiency does not destroy the hard alloy microstructure of the force of a method to deal with cemented carbide, crushing method still needs to be improved.

Posted by: hannahgwendolyn at 09:40 AM | No Comments | Add Comment
Post contains 530 words, total size 4 kb.