Filtering doesn’t work?
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In laterite ore, after nickel hydroxide is acid-dissolved, it is difficult to filter it. Basically, it cannot pass after a certain amount. But there is no residue in the filter press, but there is a little black paste-like thing on the filter cloth. I suspect it is manganese dioxide. The manganese dioxide has stuck the filter cloth and cannot filter it. Is this the case? Please give some advice.
It may be the reason you mentioned. Diatomaceous earth can be added to the filtrate to aid filtration.
Even if we add activated carbon, the filtration effect is still not very good.
This depends on whether the precision you choose is correct, and whether the filter area you choose is enough? If there are no problems with these two, you can consider adding a coarse filter device to intercept the larger particles first, and the latter will be much better. By the way, is this material particularly viscous?
It is a metal solution with a very low viscosity. It uses an ordinary chamber filter press with a capacity of 100m3. One tank of solution cannot even pass through 30m3. We filtered it three times, but it still doesn't work. Sometimes it's better, sometimes it's not. It got better after heating and hydrogen peroxide water, but after a while it became unbearable. Now I have a lot of headaches, which seriously restricts the increase in production.
I encountered this situation when doing municipal sludge dewatering. It is necessary to select a flocculant, and various factors such as variety, concentration, and stirring time will affect it. Have you tried PAM.
In laterite ore, after nickel hydroxide is acid-dissolved, it is recommended to check whether there is interference from silicic acid.
The guy upstairs wants to have a chat. It's really a silicon issue. We originally thought it was manganese dioxide, but it dropped. But after a while, I couldn’t live anymore. We have all the oil under control. It's a silicon problem. I originally reported to the superiors that the silicon content was high, but they didn't believe it. Now they believe me. The only way now is to clean the tank regularly, and filtering it is easy. I originally thought of opening the anolyte back to the miscellaneous removal section, but considering that nickel has 50g/l, it is difficult to handle. Adding lime to form nickel hydroxide is not possible. The reason why I don't want to work in this company is largely because this company values qualifications and diplomas over ability.
My QQ: 285868732 Let’s talk
I don't think it is silica colloid, because silicic acid has little effect on the viscosity of the solution when the pH is less than 2, and has good slag properties when the pH is greater than 4. If the conditions you control are between 2-4, the electronegative silica gel will absorb some positively charged particles, making filtration difficult, but this can be solved by just stopping the stirring.
I know that silicic acid is easy to handle when the pH is extremely high or extremely low. We currently require acid-soluble pH to be above 4.5. Above 4.5, precipitates will form. Only in this way can it be partially removed. Guys upstairs, please help me analyze what causes filtering difficulties. Solution: nickel 70g/l, silica 0.25g/l or more, 0.4 or less, aluminum 0.01g/l or less, calcium magnesium or magnesium 4g/l or less, lead 0.001g/l or less, manganese 2g/l or less, PH4.5~5.0