Acid cleaning systemIt can handle various products such as steel and copper parts, and has many advantages. Regarding the phosphoric acid pickling process, let's talk about the specific pickling process operations:
Due to the weak oil removal function of the prepared phosphoric acid washing solution, oily workpieces need to be degreased, while also ensuring that the pickling tank is clean and easy to regenerate.
During acid washing, the surface of the workpiece will become darker due to the action of phosphoric acid and chelating agents. The higher the carbon content, the darker the surface, but it does not affect subsequent processing.
When acid pickling with phosphoric acid, if a shorter processing time is required, it can be heated to within 45 ℃, which will greatly improve the rust removal speed. However, the temperature cannot be too high, otherwise it will have adverse effects on post-treatment.
4. Phosphoric acidAcid cleaning systemAfter pickling, if the rinsing time is too long, there may be white ash or rust, and water spraying protection should be carried out. Lowering the pickling temperature also has a certain effect. When the white ash of the workpiece is small, it does not affect the quality of phosphating. If it is not possible to ensure the occurrence of floating rust or a large amount of white ash during the water washing process, it can be solved by adding a small amount of chemical substances to the water before surface adjustment.
5. Method of adding phosphoric acid and detergent: Add when rust removal and oxidation layer slow down or pH value is greater than 2.0. The amount of phosphoric acid added is about 2% of the acid detergent, and the amount of detergent added is 1/5 of the phosphoric acid added. If necessary, anti-aging additives can be added. Anti aging additives can greatly extend the service life and regeneration time of phosphoric acid. Save phosphoric acid usage and reduce costs.
6. Phosphoric acid aging: If there is no significant change in the pickling effect after adding phosphoric acid, detergent, and anti-aging agent, regeneration treatment is needed. The simple method for determining the concentration of iron ions is as follows: take the pickling solution and dilute it with twice the amount of water, then add the diluted sodium hydroxide solution until the pH value is 7.0-7.5. Observe the turbidity of the liquid. If a large amount of white sediment is produced, it indicates an excess of iron ions and can be regenerated. The regeneration cost is relatively low, and the upper clear liquid after precipitation can be reused. Recommend using phosphoric acid regeneration additives.
7. The wastewater from the phosphoric acid pickling process can be fully reused after treatment, with zero wastewater discharge, which cannot be achieved by hydrochloric acid pickling. Recommend phosphating wastewater treatment system.
8. Phosphoric acid pickling and subsequent water washing may produce bacteria and odor when the temperature is high in summer. Adding a small amount of disinfectant can solve this problem. There are two types of fungicides: acidic and alkaline, and a simpler method is to add a small amount of formaldehyde.
9. Phosphoric acidAcid cleaning systemAcid pickling is non-toxic, harmless, odorless, cost-effective, and environmentally friendly; But there are also drawbacks, such as slightly slower pickling speed. After pickling, some steel materials may form a chemical film on their surface that darkens slightly.
10. Phosphoric acid pickling can clean various metal materials, including aluminum, copper, etc., and the rust prevention ability after pickling is much stronger than that of hydrochloric acid and sulfuric acid, and it is not harmful to the subsequent chemical solution, which is worthy of serious consideration by enterprises.
