Liquid and solid effluent treatment process
US8043585B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 2009 |
| Grant date | Oct 25, 2011 |
| Priority date | — |
| Expiry date | May 15, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/20
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A process for recovering metals such as Ni, Co, Mn, Cu, Zn, among others, through precipitation as sulphides, enabling recovery of magnesium in the form of hydroxide, carbonate and oxide and providing recovery of sulphate as gypsum and ammonium sulphate. Liquid phase, after full treatment, comprises recovered water with a quality proper for total reuse in industrial process.This process of liquid and solid effluent treatment is provided with flexibility to process several types of effluents presenting wide variations in their chemical composition. The main steps of this process are: (1) equalization of liquid effluent, (2) precipitation of metals as sulphides, (3) oxidation of metallic sulphides and crystallization as metallic sulphates, (4) precipitation of magnesium as hydroxide and calcination thereof into magnesium oxide (5) recovery of ammonia, (6) preconcentration of the remaining saline solution, (7) evaporation/crystallization of ammonium sulphate, (8) storage of recovered water, (9) partial or total precipitation of sulphate contained in the effluent with quicklime, (10) segregated storage of gypsum and gypsum-magnesium mixture, (11) softening of the remaining solution and…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.