Quality management issues in refined copper melt

:) It’s similar here to what you have there; we just put the molten copper in a channel to remove the oil from it. ;P

When our polyol plant was designed, two alcohol separation units were installed – one in the methanol section and another before copper washing and refining. There are also two copper liquid storage tanks, with 30 cubic meters of copper liquid kept on hand; the system is replaced from time to time. Of course, there is a lot of work involved in wastewater treatment and removing oil contaminants.

It can be fed into a precision filter for automatic filtration through pumping circulation, and then regenerated to remove impurities before being used again.

I mainly think that daily maintenance is aimed at ensuring that all the various parameters of the copper melt are within the proper range. Are you from Hubei Yihua? Is that a subsidiary of theirs? ? ?

There’s also Hubei Yihua – let’s introduce them all, Shuanghuan

The quality of the molten copper ultimately depends on the filter. Our system has three filters connected in parallel. Previously, the copper melt was often contaminated, but things improved a lot after installing a new filter made in Guilin. To ensure the quality of the copper melt, the filter must be cleaned regularly.

I am a new student in Zaohua, assigned to the refining position. We have had one liquid leakage incident in no particular month. It’s also because the composition of the copper melt was too dirty~~ Later, a filter was added, and there was a noticeable improvement in the situation~~~ Does the technician upstairs have any pictures of the new type of filter produced in Guilin? If you have any, could you send them to me? Thank you first~~~ Zao Hua: Cao Cheng QQ: 279708662

There are no electronic versions of the drawings. However, the choice of filter mainly depends on the filler; in the past we even used towels for filtering. Now dried loofahs are used, and the results are quite good.

The most crucial thing is to prevent contamination of the copper melt: 1. Improve the oil-water separation in the compressor and the oil separator at the inlet of the copper washing unit； 2. Reduce the H2S content in the gases entering the copper washing system, thereby minimizing the formation of copper sulfide ； 3. Reduce the CO2 content in the gas entering the copper cleaning system, thereby minimizing the formation of ammonium carbonate crystals. If the copper melt is still quite dirty, installing a precision filter like the one on floor 7 to filter out part of the copper melt can yield good results.

The composition of copper melt is quite complex. To address the issue of contamination in copper melt, I believe it is necessary to take proper measures in the following areas: 1. Strict control should be exercised during the preparation of the copper melt, to prevent oil or other solid impurities from entering the system； 2. The oil-water separation of the process gas must be thorough; the raw gas coming from the fifth stage of the compressor (or the sixth stage in case of multi-stage compressors) contains a high level of oil and water, mainly due to the inadequate performance of the oil-water separators between the compressor stages (small size and high flow rate). Therefore, an oil-water separator must be installed before the copper washing process. If the company’s resources permit, it is recommended to use a high-efficiency oil separation element in order to completely prevent oil and water from entering the copper washing system. 3. The H2S issue in the feed gas is unavoidable, so the formation of precipitates is also inevitable; due to its cumulative effect, the problem becomes apparent over time. Therefore, a copper melt filter should be installed; this type of filter uses corundum or fiber filters, which offer a high filtration precision of 5 microns, and it operates on a side-filtering principle. The copper melt is introduced into the filter using system backpressure; the clean copper melt flows back into the sump, where it is then pumped back into the system using a dirty copper pump. The copper melt filter can be regenerated using ammonia and compressed air. There are many domestic manufacturers at present, each with its own strengths. After one cycle of operation (depending on the total amount of copper melt in the system and the capacity of the copper melt filter), a fairly good result should be achieved.

We once used those microporous filters, but they got clogged easily so we stopped using them; instead, we reverted to the traditional method of using dried loofahs for filtration. These are cleaned once a week, and the oil and sediment in the tank are removed regularly during each shift. As long as the hydrogen sulfide levels aren’t high, this method works quite well. In fact, the circulation of molten copper in the underground tank is itself a process of precipitation and purification; it would be even better to prepare more molten copper for storage and then use it in a rotational manner on a regular basis.

Right! I think so too; it’s mainly the cloth used for filtering! We have also used ceramic filters, and the results weren’t that good! Later, a plate and frame filter was used (the cloth was a kind of white cloth bought on the street; I can’t even remember its name), and the results were pretty good! Several companies have come for a visit~~:) :lol

Oh, there’s another issue: the copper melt that leaks down beneath the plate and frame filter tends to crystallize into solids. I’m not sure what to do with these solids ?

Agreeing to the above, an additional point is the separation of oil from copper pumps; if the oil seal of a copper pump fails, leaks will occur, and oil will mix with the copper melt and enter the copper melting system through the recovery pipelines. Oil adheres to the electrolytic copper, affecting the composition of the copper melt. In severe cases, it affects total copper. We have encountered this phenomenon before. Later, a partition was added to the copper pump, allowing the oil and the copper melt to be recovered separately, with fairly good results.

Haha, there’s a colleague from Yihua here!

Copper washing without methanol is not easy to carry out. For copper washing, it is essential to properly control the quality of the material fed into the tower. Especially plants without ligroin. Hydrogen sulfide is the biggest menace. Next is carbon dioxide (the levels must not exceed the specified limits for long periods). The filtration of copper melt involves removing any sediment present in the troughs and storage tanks, and such sediment should not be reintroduced into the system. It is necessary to strictly control the composition of the copper melt in order to prevent precipitation from occurring. Quality management of copper melt must start from the source