Process for recovery of fluoride from wastewater produced in crystalline silicon solar cell manufacturing
US9469549B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 2013 |
| Grant date | Oct 18, 2016 |
| Priority date | — |
| Expiry date | Nov 28, 2034 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W10/37
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for processing fluoride-containing wastewaters from a factory, which includes the following steps: Step 1: collecting the fluoride-containing wastewaters into three pools: an acidic high-fluoride wastewater, an acidic low-fluoride wastewater, and an alkaline wastewater; Step 2: adding a calcium compound to the acidic low-fluoride wastewater to produce a calcium-containing solution; Step 3: reacting a portion of the calcium-containing solution with the acidic high-fluoride wastewater at a calcium-to-fluoride molar ratio of from about 0.5:1 to about 1.5:1 to produce a mixture comprising calcium fluoride particles suspended in a mother liquor; Step 4: separately collecting the calcium fluoride particles and the mother liquor; Step 5: diluting the mother liquor with a diluent to produce a mixed solution; and Step 6: introducing the mixed solution, the calcium-containing solution, and the alkaline wastewater into a fluidized bed reactor, which contains a calcium fluoride crystallization seed material, to form calcium fluoride crystals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.