New technology to carry out the epochal recycling system to "wet oxidation method" in bold challenge ~
Recycling tungsten required by the market, to achieve a steady supply of roads
The reuse of the superhard tools, sumitomo electric group in the past have been using the direct method called "zinc processing method".This method is to solid hard chip and zinc after heated to melt together, get rid of the zinc alone, then folded into a spongy hard alloy, powder recycle as recyclable.In short, is to make direct regeneration into powder composition method.Advantage of zinc treatment reagents and less energy consumption, but there is also a big problem.Although under high temperature treatment of volatile impurities can be removed, but was unable to realize high purity.In addition, also cannot adjust powder particle size.Therefore, second time use scope is limited.In this context, sumitomo electric group started to challenge for thorough recycling of hard alloy.Is made from recycled scraps with ore refining the same quality of raw materials.If can achieve, then recycling tungsten can be used for various purposes, set up a steady supply of tungsten.Therefore, must be developed to replace tungsten recovery of zinc treatment using new technology.
Regeneration into available raw materials of high purity "recycling
In 2005, the price of the tungsten soared, it has become a research and design of the new technology.Its price rose about four times as the year before, relying on the risk of tungsten imports from China into a reality.Participate in Japan's independent oil and gas and metal mineral resources of administrative legal person institution (JOGMEC) dominant project "rare metals and other high efficient recycling system development business", the group began to promote recycling tungsten for the development of new technology.As of 2007.Members development institutions including sumitomo electric industries, sumitomo electric industries cemented carbide co., LTD, the joint material co., LTD (hereinafter referred to as "joint material") and the university of Nagoya.Joint research and development are mainly concentrated in the content of the hard alloy scrap, to develop even small efficient handling of the new technology of recycling.Research and development, joint materials play a leading role.The company is a wholly owned subsidiary of sumitomo electric group, quite so group within the department of industrial raw materials, and its two big business pillars are tungsten and molybdenum the refinement of high melting point metal materials, manufacturing and processing, and diamond precision tooling and precision machining operations.As a new technology of recycling is one of the development team members, the joint material powder alloy division technology minister frequently mori thinks, new technology of recycling the ultimate goal is to ensure that the settlement "high purity"3.He said:
"By dealing with legal system into the recycling of zinc powder limited use, its purpose is also limited in hard alloy material, therefore has not come in the true sense of recycling.Real recycling refers to the free regeneration into extensive use of raw materials, namely the state before the return to processed into the WC.That is a kind of and refined ore content have the same quality of raw materials, namely, settlement of high purity3.In addition, the new technology also must be able to apply to all kinds of chip.A new technology called "wet oxidation method implements these elements, it can be processed for chemical decomposition and dissolved after the recovery of its composition.And establish the technology process, we met many difficulties."(frequently)
Implement efficient "ion exchange resin method"
Frequently points out one of the "pull" is to use molten salt dissolving technology development.To get the settlement3, the first thing to oxidizing roasting superhard tool chip, then carries on the chemical dissolution, get the solution.But it is difficult to oxidation to chip inside, need to oxidation, again lead to higher processing costs.Constantly launched a challenge to the subject.
"We use technique development, is to express the strong oxidation of sodium nitrate (NaNO3) dissolved with superhard tool chip, at the same time of oxidation, reaction with sodium.Its advantage is that can be oxidized to chip inside.But there is a big problem.Oxidation reaction with a large amount of heat, so how to control the sharp exothermic, how do you ensure that safety?After all kinds of discussion, of molten salt, the NaNO3After the optimization of the supply of, and finally realize the reaction control."(frequently)
Next, must also will generate tungsten acid sodium (Na2send4Converted to ammonium tungstate () solution (NH4)2send4) solution.Frequently, such as team member's goal is to achieve high efficiency.At that moment, everybody began to focus on "ion exchange treatment", namely to aqueous solution through the resin column filled with ion exchange resin.Let the Na2send4Tungstate ions contained in the solution attached to the ion exchange resin, obtained after using ammonium (NH4)2send4Solution.
"How to achieve high efficiency?At the same time of selected the most suitable resin, this we can look at to show the strength of the acid and alkaline pH.Through proper control of pH, we found the way to high efficiency change, makes the ion exchange treatment efficiency to previous technology from 2 to 3 times.Tungsten adsorption quantity, in other words, up to 2 to 3 times, through make equipment more compact efficiency."(frequently)
In the search for a new road for recycling enterprise in the expanded
In addition to the above subject, team members also addressed a variety of topics, such as exhaust gas disposal, ammonia recovery and secondary utilization of the system, discuss about powder chip proper recycled etc, to build up a complete tungsten recycling system.Complete sets of equipment in 2010 began to run, and then through perfecting, began in earnest in the second half of 2011.
"From the scraps as raw materials to the final carbonization process, we always attach great importance to quality.In the future, we hope to further expand recycling business.Due to the existing production site toyama production can be used to increase the space is limited, we will explore new ways."(frequently)
Frequently referred to the recycling business expansion.Now, we are a group that the United States promote its related to try.The next chapter will introduce introduced into "wet oxidation method" in the United States to promote the recycling of relevant measures.
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In the United States to develop tungsten recycling business
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