CN105776781A

CN105776781A - Method for reducing fluosilicate in sludge of photovoltaic industry

Info

Publication number: CN105776781A
Application number: CN201610194689.5A
Authority: CN
Inventors: 石坚; 毛维东; 王振
Original assignee: Shandong Chenyu Rare Material Technology Co Ltd
Current assignee: Shandong Chenyu Rare Material Technology Co Ltd
Priority date: 2016-03-30
Filing date: 2016-03-30
Publication date: 2016-07-20

Abstract

The invention discloses a method for reducing fluosilicate in sludge of the photovoltaic industry. The method comprises the following steps: (1) performing air-blowing stirring on a pool for storing sludge, adding a sodium hydroxide solution, stopping adding the sodium hydroxide solution when the pH value is within 11.5-12, and keeping for 24 hours; (2) adding a calcium chloride solution into the pool, and adding once every 24 hours; (3) when the concentration of fluorine ions is less than 1mg/L, adding a waste acid solution into the pool, and stopping air-blowing stirring and addition of the waste acid when the pH value is stabilized within 7.5-8.5; and (4) pumping out the sludge of which fluosilicate is removed from the pool. On the basis of the principle that hydroxy radicals and fluosilicic acid radicals can be reacted to replace out the fluorine ions in a strong base environment, the content of inorganic fluoride with sludge leaching toxicity can be reduced, that is, the content is lower than the national standard of that of the dangerous waste inorganic fluoride with sludge leaching toxicity.

Description

A kind of reduce the method for fluosilicate in photovoltaic industry mud

Technical field

The invention belongs to technical field of sewage, be specifically related to a kind of reduce the side of fluosilicate in photovoltaic industry mud Method.

Background technology

At present, the way of photovoltaic industry FLUORIDE REMOVAL IN WASTEWATER ion generally uses the calcium salt precipitation method of low cost, but in waste water The nearly 1000mg/L of content of fluoride ion, the highest, substantial amounts of mud can be produced with calcium precipitation, this mud is former due to production technology Cause, composition is extremely complex containing various heavy；Entrust the composition of third party testing agency detection mud, inorganic fluoride content Reach 203mg/L, be much higher than the limit value of the 100mg/L of GB5085.3 2007 regulation, and become hazardous waste, not only dirty Dye environment, and 10 times of the processing cost of hazardous waste usually normal refuse processing cost, increase business burden.

Summary of the invention

It is an object of the invention to provide and a kind of reduce the method for fluosilicate in photovoltaic industry mud, it can be by mud The content of the fluosilicate of Leaching reduces, and is converted into and does not has virose solid precipitation, decreases environmental pollution, drops simultaneously The Di Liao enterprise processing cost to fluorine-containing sludge.

The present invention solves its technical problem and is adopted the technical scheme that: fluosilicate in a kind of reduction photovoltaic industry mud Method, comprise the steps:

(1) make pending mud natural sedimentation 24 hours, draw up clear liquid with water pump so that it is be maintained at away from the Sludge Surface degree of depth 10-15cm；

(2) in the pond deposit mud, carry out air-blowing stirring, and add sodium hydroxide solution, add one every 24 hours Secondary, add sodium hydroxide solution according to the volume ratio of 1000:1 every time, the pH value of test mud, when surveyed pH value is at 11.5-12 Between time, stop the addition of sodium hydroxide solution, and keep 24 hours；Reaction equation is: 6OH^- + [SiF₆]^2- = SiO₃ ^2- + 6F^- + 3H₂O

(3) adding calcium chloride solution in pond, within every 24 hours, add once, the volume ratio every time added is similarly 1000:1；And measure the concentration of fluorion in pond, reaction equation: Ca²⁺ + 2F^- = CaF₂↓；

(4) when the concentration of fluorine example is stabilized to below 1mg/L, then in pond, add waste acid liquor, and test its pH Value, when pH stable is between 7.5-8.5, stops bubbling stirring and the addition of spent acid；

(5) mud removing fluosilicate is extracted out from pond；And the mud drip of fluosilicate will be removed with pressure filter Dry.

The concentration of described sodium hydroxide solution is 0.5kg/L.

The concentration of described calcium chloride solution is 0.6kg/L.

As long as the purpose that the present invention adds sodium hydroxide solution makes mud be in strong alkali environment, under strong alkali environment, hydrogen Oxygen radical ion cements out the fluorine in hexafluosilicic acid radical ion, and the calcium chloride that the fluorion cemented out and later stage add reacts raw Become calcium fluoride precipitate, reduce the content of fluosilicate in mud.

The invention has the beneficial effects as follows: the inventive method utilizes hydroxyl under strong alkali environment to react with hexafluosilicic acid root and puts Swap out the principle of fluorion, is reduced by the content of the fluosilicate of mud Leaching, and be converted into and do not have virose solid to sink Form sediment, decrease environmental pollution, reduce enterprise's processing cost to fluorine-containing sludge simultaneously, be conducive to recycling；It is disposed The content of rear third party testing agency detection inorganic fluoride have decreased to 31mg/L, inorganic less than the hazardous waste of national regulation The national standard of fluoride Leaching content, the beneficially popularization and application of enterprise.

Accompanying drawing explanation

Fig. 1 is the changing trend diagram of fluorine ion concentration in the embodiment of the present invention.

Detailed description of the invention

Technical scheme is further illustrated below by specific embodiment.

A kind of reduce the method for fluosilicate in photovoltaic industry mud, comprise the steps:

(1) make 1 ton of natural sedimentation of pending mud 24 hours, draw up clear liquid with water pump so that it is protect away from the Sludge Surface degree of depth Hold at 10cm；

(2) carrying out air-blowing stirring in the pond deposit mud, and add sodium hydroxide solution 100L, concentration is 0.5kg/ L, added once every 24 hours, adds 100L every time；The pH value of test mud, when surveyed pH value is between 11.5-12, stops The only addition of sodium hydroxide solution, and keep 24 hours；Reaction equation is: 6OH^- + [SiF₆]^2- = SiO₃ ^2- + 6F^- + 3H₂O；

(3) adding calcium chloride solution 100L in pond, concentration is 0.6kg/L, within every 24 hours, adds once；And measuring cell The concentration of fluorion in son；Added calcium chloride solution in this step；Reaction equation: Ca²⁺ + 2F^- = CaF₂↓；

(4) when the concentration of fluorine example is stabilized to below 1mg/L, then in pond, add waste acid liquor, and test its pH Value；Bubbling stirring and the addition of spent acid is stopped when pH stable is about 8；

(5) mud removing fluosilicate is extracted out from pond；

(6) with pressure filter, the mud removing fluosilicate is drained.

Fig. 1 show the changing trend diagram of fluorine ion concentration, and the inventive method utilizes hydroxyl and fluorine silicon under strong alkali environment Acid group reacts and displaces the principle of fluorion, is reduced by the content of the fluosilicate of mud Leaching, and is converted into not Virose solid precipitation, decreases environmental pollution, reduces enterprise's processing cost to fluorine-containing sludge simultaneously, is conducive to reclaiming Utilize；After being disposed, the content of third party testing agency detection inorganic fluoride drops to below 31mg/L, less than state's domestic discipline and family rules The national standard of fixed hazardous waste inorganic fluoride Leaching content, the beneficially popularization and application of enterprise.

In addition to technical characteristic described in description, it is those skilled in the art known technology.

Claims

1. one kind is reduced the method for fluosilicate in photovoltaic industry mud, it is characterised in that: comprise the steps:

(1) make pending mud natural sedimentation 24 hours, draw up clear liquid with water pump so that it is away from Sludge Surface

The degree of depth is maintained at 10-15cm；

(2) in the pond deposit mud, carry out air-blowing stirring, and add sodium hydroxide solution, added once every 24 hours, Adding sodium hydroxide solution according to the volume ratio of 1000:1, the pH value of test mud, when surveyed pH value is between 11.5-12 every time Time, stopping the addition of sodium hydroxide solution, and keep 24 hours, reaction equation is: 6OH^- + [SiF₆]^2- = SiO₃ ^2- + 6F^- + 3H₂O；

(3) adding calcium chloride solution in pond, within every 24 hours, add once, the volume ratio every time added is similarly 1000:1； And measure the concentration of fluorion in pond, reaction equation: Ca²⁺ + 2F^- = CaF₂↓；

(4) when the concentration of fluorine example is stabilized to below 1mg/L, then in pond, add waste acid liquor, and test its pH value, treat When pH stable is between 7.5-8.5, stop bubbling stirring and the addition of spent acid；

(5) mud removing fluosilicate is extracted out from pond；And with pressure filter, the mud removing fluosilicate is drained.

The method of fluosilicate in reduction photovoltaic industry mud the most according to claim 1, it is characterised in that: described hydrogen-oxygen The concentration changing sodium solution is 0.5kg/L.

The method of fluosilicate in reduction photovoltaic industry mud the most according to claim 1, it is characterised in that: described chlorination The concentration of calcium solution is 0.6kg/L.