CN101638260A - Method for preparing polymeric aluminum sulfate silicate by recycling activated clay industrial wastewater - Google Patents

Abstract

The invention discloses a method for preparing polymeric aluminum sulfate silicate by recycling activated clay industrial wastewater, which is characterized by taking a sodium silicate solution having10-20 percent by weight of silicon dioxide; adjusting the pH value by using the active clay industrial wastewater in stirring; adjusting to obtain a solution with 1.0-4.8 percent by weight of the final concentration; stirring the solution to react; placing the solution to the room temperature and using the solution as a backup silicic acid solution; adding aluminum hydroxide into the activated clay industrial wastewater to heat and stir; adjusting the pH value by using sodium hydroxide after the aluminum hydroxide is completely reacted with sulfuric acid; evaporating and concentrating into analuminum sulfate solution; adding the aluminum sulfate solution into the backup silicic acid solution; controlling the mol rate of aluminum and silicon into 2.0-5.0; and stirring and reacting to obtain polymeric aluminum silicate-sulfate flocculant with 40,000-200,000 of average molecular weight. The method has the advantages of no secondary pollution, more simplified process, lower cost and moreexcellent product property.

Description

The method of preparing polymeric aluminum sulfate silicate by recycling activated clay industrial wastewater

Technical field

The invention belongs to fields such as waste water treatment and water conditioner preparation.

Background technology

Atlapulgite is mainly used in the decolorizing and refining of mineral oil, vegetables oil and animal grease, is a kind of important petrochemical complex and daily-use chemical industry raw material.China's atlapulgite annual consumption is about 400,000 tons at present.

Atlapulgite is to be raw material with the wilkinite, mainly adopts the wet process acid metallization processes to process.Its production process comprises: the wilkinite aquation, add sulfuric acid activation, washing, dry, pulverize.Because of its product acid content is big, need just can make acid content less than 0.2%, to reach the requirement of HG/T2569-94 product standard through washing repeatedly.According to the method difference, the wastewater flow rate that water washing process produces has certain difference, generally is no less than 30～40 tons but produce the wastewater flow rate that 1 ton of atlapulgite produces.Mainly contain Tai-Ace S 150 that the wilkinite acidification reaction produces and unreacted sulfuric acid etc. in this waste water,, not only wasted a large amount of resources, and can cause serious pollution environment if directly discharge.

In recent years, improvement and recycling at activated clay production waste have proposed certain methods, as lime neutralisation, Wingdale neutralisation, carbide slag neutralisation, time acid activation method, reach with it and decompose china clay with process industry water conditioner Tai-Ace S 150, at iron and steel and the industrial pickling agent of doing of goods thereof, the dissolving iron filings are made green vitriol etc.These methods, the governing problem that has solved activated clay production waste preferably that has, can make the acidity in the waste water obtain neutralization as the lime neutralisation by adding lime, make precipitation such as formation calcium sulfate, aluminium hydroxide, ironic hydroxides such as sulfate ion, aluminum ion and iron ion and remove, but these throw outs because of can not obtain utilizing become new solid useless; The recycling problem of resource in the activated clay production waste that solved preferably that has, is exactly to utilize sulfuric acid in waste water decompose china clay with process industry with the method for water conditioner Tai-Ace S 150 as decompose china clay with it, aluminium in the china clay is leached solution, again through purification and impurity removal, evaporative crystallization, separate dry, crushing packing gets Tai-Ace S 150, although this method has effectively utilized the sulfuric acid in the activated clay production waste, resources such as Tai-Ace S 150, but because impurity such as iron ion can influence the quality of product Tai-Ace S 150, thereby must be removed through the purification and impurity removal process, so make its reparation technology comparatively complicated, raw material consumption is more, causes productivity effect not good.

Polymeric aluminum sulfate silicate is a kind of novel inorganic polymeric flocculant, is the poly-silicic acid that grows up on the basis of poly-silicic acid and aluminum salt flocculant and the combination product of aluminium salt.Because therefore advantages such as this flocculation agent has that flocculating effect is good, the residual aluminium amount behind the low price, processing in the water is low have caused the very big concern of domestic and international field of water treatment to its research.This flocculation agent is main at present to adopt industrial goods such as water glass, sodium aluminate and Tai-Ace S 150 to make through polyreaction as raw material.Comparatively speaking, the raw materials for production cost is higher.

Summary of the invention

The present invention is for avoiding above-mentioned existing in prior technology weak point, a kind of method that can not bring the preparing polymeric aluminum sulfate silicate by recycling activated clay industrial wastewater that secondary pollution, technology are more simplified, cost is lower, product performance are more excellent being provided.

Technical solution problem of the present invention adopts following technical scheme:

The characteristics of the method for preparing polymeric aluminum sulfate silicate by recycling activated clay industrial wastewater of the present invention are to carry out as follows:

The first step: get the sodium silicate solution that the silica weight percentage concentration is 10-20%, under agitation regulating the pH value with activated clay production waste is 4.0-5.5, and adjusting acquisition silicon-dioxide ultimate density is the solution of 1.0-4.8% by weight percentage, described solution placed under 30-60 ℃ the temperature environment, after stirring reaction 5-16 hour, stop to stir and placing under the room temperature, be standby silicate solution;

Second step: in activated clay production waste, add aluminium hydroxide, the add-on of described aluminium hydroxide is the 40-50% of sulfuric acid weight in the activated clay production waste, heated and stirred to aluminium hydroxide and sulfuric acid reaction is regulated the pH value to 3.5-5.5 with sodium hydroxide in the back fully, is the alum liquor of 10-22% for the Tai-Ace S 150 weight percent concentration with its evaporation concentration again;

The 3rd step: step 2 gained alum liquor is joined in the standby silicate solution of step 1 gained, and control aluminium silicon mol ratio is 2.0-5.0, and promptly getting molecular-weight average behind the stirring reaction is the polymeric aluminum sulfate silicate flocculation agent of 40000-200000.

Compared with the prior art, beneficial effect of the present invention is embodied in:

1, the present invention can all recycle activated clay production waste, and can not produce secondary pollution in the recycling process;

2, the inventive method is compared with the polymeric aluminum sulfate silicate with industrial raw material production, and production cost is low, and in the product of producing because of containing a spot of iron, its flocculating property is more excellent;

3, with activated clay production waste decomposition china clay compare with water conditioner Tai-Ace S 150 method with process industry, the present invention because of need not deironing, so simplified reparation technology, has reduced raw material consumption in producing the polymeric aluminum sulfate silicate process.

Polymeric aluminum sulfate silicate flocculating experiment scheme is:

In the floc test, adopt Chaohu Yuan Shui as actual water sample.Get the 500mL water sample, add 40 μ L polymeric aluminum sulfate silicates, stirred fast 1 minute, stirred at a slow speed again 4 minutes, left standstill 1 hour.Get 2-3cm place, upper strata clear liquid and survey its absorbancy, calculate its turbidity and turbidity removal rate.

Description of drawings

Fig. 1 is a process flow sheet of the present invention.

Fig. 2 is used for the flco of the former water generates in Chaohu for polymeric aluminum sulfate silicate of the present invention.

Fig. 3 is the water quality situation of polymeric aluminum sulfate silicate of the present invention after to the former water treatment in Chaohu.

Embodiment

Embodiment 1:

The present embodiment technical process as shown in Figure 1, the concrete operations step is as follows:

Step 1, get the silica weight percentage concentration and be 12% sodium silicate solution, under agitation regulate pH value to 5.2 with activated clay production waste, and to make silicon-dioxide final weight percentage concentration be 1.1%, place under 58 ± 1 ℃, continue stirring reaction after 7 hours, stop to stir and placing under the room temperature, be standby silicate solution;

Step 2 adds aluminium hydroxide in activated clay production waste, heated and stirred to aluminium hydroxide and sulfuric acid reaction is regulated pH value to 5.2 with sodium hydroxide in the back fully, is 18% alum liquor again for the Tai-Ace S 150 weight percent concentration with its evaporation concentration;

Step 3 when the speed of pressing 1500r/min stirs, joins step 2 gained alum liquor in the first step gained silicate solution, and control aluminium silicon mol ratio is 4.8; React that can to get molecular-weight average after 1 hour be 56000 polymeric aluminum sulfate silicate flocculation agent.Because of containing small amounts of iron in the product, so be light yellow.

The flocculating experiment result of this product is: when Chaohu raw water turbidity was 41.0NTU, the residual turbidity of handling back water was 0.40NTU, and the turbidity removal rate is 99%.When Chaohu raw water turbidity was 114NTU, the residual turbidity of handling back water was 2.0NTU, and the turbidity removal rate is 98%.Flocculating effect as depicted in figs. 1 and 2.

Embodiment 2:

The present embodiment technical process as shown in Figure 1, the concrete operations step is as follows:

Step 1, get the silica weight percentage concentration and be 15% sodium silicate solution, under agitation regulate pH value to 4.3 with activated clay production waste, and to make silicon-dioxide final weight percentage concentration be 2.2%, place under 50 ± 1 ℃, continue stirring reaction after 10 hours, stop to stir and placing under the room temperature, be standby silicate solution;

Step 2 adds aluminium hydroxide in activated clay production waste, heated and stirred to aluminium hydroxide and sulfuric acid reaction is regulated pH value to 4.3 with sodium hydroxide in the back fully, is 16% alum liquor again to the Tai-Ace S 150 weight percent concentration with its evaporation concentration;

Step 3 when the speed of pressing 1700r/min stirs, joins step 2 gained alum liquor in the first step gained silicate solution, and control aluminium silicon mol ratio is 3.8; React that can to get molecular-weight average after 2 hours be 75000 polymeric aluminum sulfate silicate flocculation agent.

The flocculating experiment result of this product is: when Chaohu raw water turbidity was 41.0NTU, the residual turbidity of handling back water was 0.70NTU, and the turbidity removal rate is 98%.When Chaohu raw water turbidity was 114NTU, the residual turbidity of handling back water was 4.6NTU, and the turbidity removal rate is 96%.

Embodiment 3

The present embodiment technical process as shown in Figure 1, the concrete operations step is as follows:

Step 1, get the silica weight percentage concentration and be 18% sodium silicate solution, under agitation regulate pH value to 3.6 with activated clay production waste, and to make silicon-dioxide final weight percentage concentration be 4.0%, place under 35 ± 1 ℃, continue stirring reaction after 15 hours, stop to stir and placing under the room temperature, be standby silicate solution;

Step 2 adds aluminium hydroxide in activated clay production waste, heated and stirred to aluminium hydroxide and sulfuric acid reaction is regulated pH value to 3.6 with sodium hydroxide in the back fully, is 12% alum liquor again to the Tai-Ace S 150 weight percent concentration with its evaporation concentration;

Step 3 when the speed of pressing 1900r/min stirs, slowly joins the second step gained alum liquor in the first step gained silicate solution, and control aluminium silicon mol ratio is 2.5; React that can to get molecular-weight average after 2 hours be 82000 polymeric aluminum sulfate silicate flocculation agent.

The flocculating experiment result of this product is: when Chaohu raw water turbidity was 41.0NTU, the residual turbidity of handling back water was 1.2NTU, and the turbidity removal rate is 97%.When Chaohu raw water turbidity was 114NTU, the residual turbidity of handling back water was 1.6NTU, and the turbidity removal rate is 99%.

Claims (1)

1, the method for preparing polymeric aluminum sulfate silicate by recycling activated clay industrial wastewater is characterized in that carrying out as follows:

Step 1: get the sodium silicate solution that the silica weight percentage concentration is 10-20%, under agitation regulating the pH value with activated clay production waste is 4.0-5.5, and adjusting acquisition silicon-dioxide ultimate density is the solution of 1.0-4.8% by weight percentage, described solution placed under 30-60 ℃ the temperature environment, after stirring reaction 5-16 hour, stop to stir and placing under the room temperature, be standby silicate solution;

Step 2: in activated clay production waste, add aluminium hydroxide, the add-on of described aluminium hydroxide is the 40-50% of sulfuric acid weight in the activated clay production waste, heated and stirred to aluminium hydroxide and sulfuric acid reaction is regulated the pH value to 3.5-5.5 with sodium hydroxide in the back fully, is the alum liquor of 10-22% for the Tai-Ace S 150 weight percent concentration with its evaporation concentration again;

Step 3: step 2 gained alum liquor is joined in the standby silicate solution of step 1 gained, and control aluminium silicon mol ratio is 2.0-5.0, and promptly getting molecular-weight average behind the stirring reaction is the polymeric aluminum sulfate silicate flocculation agent of 40000-200000.