CN102515323A - Method for preparing high efficiency nontoxic purifying agent by industrial waste - Google Patents

Abstract

The invention discloses a method for preparing high-efficiency non-toxic water purifying agent by using industrial waste, which relates to the preparation of polysilicate cationic coagulant with waste sulfuric acid and industrial waste residue as main raw materials, which is prepared from industrial waste residue pickling solution, polysilicic acid Preparation, polysilicate cation preparation three-step process composition. The method simplifies the preparation process, reduces the cost, effectively utilizes industrial wastes and reduces environmental pollution. The prepared high-efficiency non-toxic water purifier has stable performance and less dosage. In the advanced treatment of wastewater, its turbidity, chromaticity and COD removal effects are significantly better than traditional water purifiers such as PAC. The effluent water quality is good and the aluminum residue Low content, no harmful substances such as chlorine and heavy metals, and no iron ion water phase transfer, non-toxic, harmless, safe and reliable.

Description

Method for preparing high-efficiency non-toxic water purifying agent from industrial waste

technical field

The invention belongs to an inorganic macromolecular flocculant for waste water treatment, and in particular relates to a preparation method of polysilicate cations.

Background technique

my country produces nearly one million tons of waste sulfuric acid and tens of millions of tons of industrial waste residue every year. These wastes have a low utilization rate and are mostly stacked in the open air, which greatly wastes resources and energy and aggravates environmental pollution.

In recent years, with the development of my country's social economy and the improvement of people's living standards, the requirements for environmental protection have become higher and higher, and the standards for sewage discharge have become more stringent. A large number of highly efficient and non-toxic water purifiers.

Polysilicate coagulant is a new type of inorganic polymer coagulant developed on the basis of activated silicic acid and traditional aluminum salt, iron salt and other coagulants in the 1990s. Silicon is anionic and negatively charged, and metal Cations are positively charged, and their unit molecular weight in the aqueous solution state is about hundreds to thousands, and they can combine with each other to form oligomers, middle polymers and high polymers of different sizes and structures. It combines the advantages of polysilicic acid and polymetallic ions, and at the same time has the functions of electrical neutralization, adsorption bridging and net capture, and has good coagulation effect. Now it has become the mainstream of coagulant research. However, most of its preparations use chemical agents as raw materials, and the cost is high. There are also studies on the preparation of polyaluminum iron silicate from fly ash and other wastes, but the process is complicated, the requirements for raw materials and equipment are high, and the product effect is unstable. The time is shorter. Described as CN1594082A with fly ash, ironmaking slag, sodium hydroxide, sodium carbonate, sulfuric acid and hydrochloric acid, through eight-step process, and needs the special process of preparing polyaluminosilicate ferric under certain pressure conditions. CN1830828A introduces the method of preparing polyaluminum-ferric silicate composite flocculant by using fly ash, ferrous sulfate, industrial soda ash and industrial hydrochloric acid as raw materials, and undergoing three steps of high-temperature roasting at 800-900°C, heating and stirring impregnation, and centrifugal filtration and separation.

Contents of the invention

The purpose of the present invention is to improve the deficiencies of the above-mentioned existing coagulants, and to provide a method for preparing an efficient and non-toxic water purifier from industrial waste. The prepared water purifier is suitable for advanced treatment of sewage, with stable performance and excellent effect The method is excellent, and the preparation process is simple, the cost is low, no harmful waste is produced, and it is suitable for popularizing industrial production.

Technical scheme of the present invention solves like this:

The method for preparing high-efficiency non-toxic water purifying agent with industrial waste provided by the present invention includes using waste sulfuric acid and industrial waste residue as main raw materials,

(1) Preparation of industrial waste residue pickling solution, get waste sulfuric acid and add in industrial waste residue, stir for 1-2 hours, the liquid-solid mass ratio is 2-5, filter, and the filtrate is metal hydrochloric acid dipping solution;

(2) Preparation of polysilicic acid, take waste sulfuric acid solution, and slowly add _SiO2 mass fraction of 2-5% water glass solution under sufficient stirring conditions until the pH value of the solution is 1-3, and continue stirring for 5-60 minutes Stop to obtain polysilicic acid solution;

(3) Preparation of polysilicate cation: under the condition of sufficient stirring, add industrial waste residue acid immersion solution into the polysilicate solution at a volume ratio of 1:0.5-2 by copolymerization method, and then slowly add sodium hydroxide solution until the pH value is 0.1 -3, and add water to the predetermined volume, stir and mix, and the preparation is complete.

The high-efficiency non-toxic water purifying agent of the present invention uses waste sulfuric acid, industrial waste residues and other industrial wastes as main raw materials, provides a method for reusing these wastes, and reduces environmental pollution. The method simplifies the preparation process into three major steps and reduces the cost. The performance of this high-efficiency non-toxic water purifier: the advanced treatment test of papermaking wastewater shows that compared with traditional flocculants such as PAC, the best removal rates of COD, turbidity and chroma are increased by 21%, 5% and 33% respectively , The residual total aluminum content in the effluent is reduced by 61%. It does not contain harmful substances such as chlorine and heavy metals, and there is no iron ion water phase transfer. It is non-toxic, harmless, safe and reliable. In addition, the pH and total alkalinity of the effluent have small changes, and are less corrosive to the treatment equipment.

Detailed ways

Example 1

(1) Preparation of industrial waste residue pickling solution, take waste sulfuric acid and add it to industrial waste residue, stir for 1 hour, the liquid-solid mass ratio is 3, filter, and the filtrate is metal hydrochloric acid dipping solution; (2) Preparation of polysilicic acid, take waste sulfuric acid solution, under sufficient stirring conditions, slowly add _SiO2 mass fraction of 2% water glass solution, until the pH value of the solution is 1.5, and stop stirring after 15 minutes to obtain polysilicate solution; (3) preparation of polysilicate cations : Under the condition of full stirring, adopt the copolymerization method to add the industrial waste residue pickling solution in the polysilicic acid solution at a volume ratio of 1:0.8, then slowly add the sodium hydroxide solution until the pH value is 0.5, and add the above-mentioned polysilicate cation 2 Double the volume of water, stir and mix, the preparation is complete.

Example 2

(1) Preparation of industrial waste residue pickling solution, take waste sulfuric acid and add it to industrial waste residue, stir for 2 hours, the liquid-solid mass ratio is 4, filter, and the filtrate is metal hydrochloric acid dipping solution; (2) Preparation of polysilicic acid, take waste sulfuric acid solution, under sufficient stirring conditions, slowly add _SiO2 mass fraction of 4% water glass solution, until the pH value of the solution is 2.5, continue stirring for 30 minutes and then stop to obtain polysilicate solution; (3) preparation of polysilicate cations : Under the condition of full stirring, adopt the copolymerization method to add the industrial waste residue pickling solution in the polysilicate solution at a volume ratio of 1:1.5, then slowly add the sodium hydroxide solution to a pH value of 1, and add the above polysilicate cation The same volume of water, stir and mix, the preparation is complete.

Example 3

(1) Preparation of industrial waste residue pickling solution, take waste sulfuric acid and add it to industrial waste residue, stir for 2 hours, the liquid-solid mass ratio is 3, filter, and the filtrate is metal hydrochloric acid dipping solution; (2) Preparation of polysilicic acid, take waste sulfuric acid solution, under sufficient stirring conditions, slowly add _SiO2 mass fraction of 3.5% water glass solution, until the pH value of the solution is 1.8, continue stirring for 40 minutes and then stop to obtain polysilicate solution; (3) preparation of polysilicate cations : Under the condition of full stirring, adopt the copolymerization method to add industrial waste slag acid immersion solution into the polysilicate solution at a volume ratio of 1:0.5, then slowly add sodium hydroxide solution to a pH value of 0.5, and add the above-mentioned polysilicate cation 1.5 Double the volume of water, stir and mix, the preparation is complete.

Example 4

(1) Preparation of industrial waste residue pickling solution, take waste sulfuric acid and add it to industrial waste residue, stir for 1.5 hours, the liquid-solid mass ratio is 4.5, filter, and the filtrate is metal hydrochloric acid dipping solution; (2) Preparation of polysilicic acid, take waste sulfuric acid solution, under fully stirring conditions, slowly add _SiO2 mass fraction of 2% water glass solution, until the pH value of the solution is 1.5, continue to stir for 60 minutes and then stop to obtain polysilicate solution; (3) preparation of polysilicate cations : Under the condition of full stirring, adopt the copolymerization method to add industrial waste slag acid immersion solution into the polysilicate solution at a volume ratio of 1:1, then slowly add sodium hydroxide solution to a pH value of 1.5, and add the above-mentioned polysilicate cation 0.5 Double the volume of water, stir and mix, the preparation is complete.

Claims (1)

1. A method for preparing efficient nontoxic water purifying agent with industrial waste, comprising taking waste sulfuric acid and industrial waste residue as main raw material, is characterized in that, comprises the following steps: 1) Preparation of industrial waste residue acid leaching solution, take waste sulfuric acid and add it to industrial waste residue, stir for 1-2 hours, the liquid-solid mass ratio is 2-5, filter, and the filtrate is the metal hydrochloride acid leaching solution; 2) Preparation of polysilicic acid, take waste sulfuric acid solution, slowly add water glass solution with _S1O2 mass fraction of 2-5% under sufficient stirring conditions, until the pH value of the solution is 1-3, continue stirring for 5-60 minutes and then stop , to obtain polysilicic acid solution; 3) Preparation of polysilicate cations, under the condition of sufficient stirring, use the copolymerization method to add industrial waste residue acid immersion solution into the polysilicate solution at a volume ratio of 1:0.5-2, and then slowly add sodium hydroxide solution until the pH value is 0.1-2. 3. Add water to the predetermined volume, stir and mix well, and the preparation is complete.