FIELD: chemistry.
SUBSTANCE: invention can be used to recycle volatile coal ash. Si is leached from volatile ash using NaOH solution with concentration of 40 wt % at 70-150 °C to obtain Na2SiO3. After leaching the Na2SiO3 solution and residue in which the ratio of Al to Si is greater than or equal to 2 are separated. Silica is obtained through carboxylation of the separated Na2SiO3 solution. CaO is added to the residue in ratio of CaO to SiO2 less than or equal to 2, and alkali is also added to the residue in ratio of Na2O to Al2O3 and Fe2O3 greater than or equal to 1-1.1. Suspended material is burnt at 950-1350°C to obtain slag which is dissolved in a diluted alkaline solution and the solid precipitate is separated from the liquid. The obtained liquid is carboxylated with precipitation of aluminium hydroxide which is then burnt to Al2O3.
EFFECT: invention enables highly efficient recycling of volatile ash.
5 cl, 7 ex
Title | Year | Author | Number |
---|---|---|---|
HYDRAULIC BINDER | 2005 |
|
RU2376252C2 |
METHOD OF PROCESSING SILICA-ALUMINA STOCK | 2013 |
|
RU2574252C2 |
GEOPOLYMER COMPOSITE BINDERS WITH GIVEN PROPERTIES FOR CEMENT AND CONCRETE | 2010 |
|
RU2517729C2 |
BATCH FOR SMELTING OF FERROALUMINUM SILICON | 2003 |
|
RU2241058C1 |
PRODUCTION OF CEMENT CLINKER | 2012 |
|
RU2555980C2 |
METHOD OF REDUCING CONTENT OF SULPHUR AND/OR MERCURY IN FLUE GASES (VERSIONS), SORBENT COMPOSITION, METHOD OF BURNING COAL WITH REDUCED EMISSION OF HARMFUL ELEMENTS INTO ENVIRONMENT (VERSIONS), COAL ASH OBTAINED USING SAID METHODS, AND CEMENT, POZZOLAN, CONCRETE MIXTURE AND MORTAR THEREOF, CONCRETE STRUCTURE, METHOD OF PRODUCING CEMENTING MIXTURE, OBTAINED BASED ON OR THROUGH SAID ASH | 2006 |
|
RU2440179C2 |
METHOD FOR COMPLEX PROCESSING OF ASH FROM BURNING COAL | 2015 |
|
RU2605987C1 |
METHOD OF PRODUCTION OF HYDRAULIC BINDER | 2000 |
|
RU2200137C2 |
METHOD TO EXTRACT METALS FROM SILICATE SLAGS | 2013 |
|
RU2515735C1 |
METHOD FOR COMPLEX PROCESSING OF RED AND NEPHELINE SLUDGES | 2014 |
|
RU2619406C2 |
Authors
Dates
2010-05-20—Published
2007-08-16—Filed