| 摘要 |
A process for providing more efficient and effective chemical stabilization of solid residues containing lead is described. The process consists of introducing into the residue, or solutions in contact with these residues, polyprotic acid oxyanions that can form insoluble acid oxyanion-lead complexes in solution. Included in this category of compounds are phosphates, borates, vanadates, selenates, arsenates, carbonates, chromates and sulfates. To maximize the effectiveness of acid oxyanion treatment of lead-bearing residues that also contain noncarbonate hardness producing elements such as calcium and magnesium, the introduction of an alkali-metal carbonate, such as sodium carbonate, along with the acid oxyanion is recommended. This alkali-metal carbonate additive can increase the solubility of acid-oxyanions, particularly in solutions with high levels of calcium and magnesium, thereby promoting the more efficient formation of insoluble lead-oxyanion complexes.
|
