KR100284368B1 - Manufacturing method of cohesive chemical - Google Patents

Abstract

The present invention is for water purification flocculants in particular, waste water purification, pulp and paper manufacturing, dewatering organic matter, inorganic matter was concentrated coagulant preparation containing a metal salt and silicate, and a solid zeolite is Me ^3+: Si molar ratio of 2: At least two, especially in a trivalent metal salt solution of 2-500: 1.

Description

Cohesive Compound Manufacturing Method

The present invention relates to a method for producing cohesive chemicals containing trivalent metal salts and silicates, for use in water purification chemicals, in particular for purification of drinking water and wastewater, agglomeration of cellulose fibers for the manufacture of paper and pulp, dehydration of organic substances, and concentration of minerals. do.

It is an object of the present invention to obtain cohesive chemicals, such as water purification chemicals, having improved cohesive and settling forces in the purification of drinking and waste water.

Chemical flocculation using inorganic cohesive chemicals has the advantage of rapidly settling particles and phosphorus-containing compounds. The particle reduction effect is very important since 60 to 75% of the wastewater COD depends on the particles. Wastewater contains organic compounds, some of which can be precipitated using inorganic salts. Using only salt can reduce 60 to 75% of the wastewater COD.

However, flocculant is used not only for wastewater purification but also for the purification of raw water for drinking water production. Moreover, when flocculating chemicals are used in the manufacture of pulp, the cellulose fibers are flocculated and the resin sizing agent is attached onto the cellulose fibers in order to agglomerate cellulose fibers and fillers in papermaking and to hydrophobize the paper. Moreover, flocculants are used to dehydrate organic matter and to concentrate minerals in the mining industry.

It is known to use polyaluminum silicate sulphate (PASS) solutions as flocculants in water purification operations (FI patent application 895163). The PASS is made by high shear mixing of aluminum sulfate, sodium silicate, and sodium aluminate. Other uses include the pulp and paper industry in addition to the mining industry.

PASS solutions are known to be effective at low temperatures, are less corrosive than iron sulfate, aluminum chloride, and polyaluminum chloride, have a lower aluminum content in the eluate, require a lower dosage, and form a faster settling floc, It is preferred in the papermaking industry because it improves adsorption, is effective over a wide pH range, requires less alkali and is free of chlorine.

This PASS solution contains the following active compounds:

Al (OH) _x (SiO _u ) _y (SO ₄ ) _z (H ₂ O) _v + Na ₂ SO ₄

Where x is from 0.75 to 2.0,

y is 0.005 to 0.1,

z is 0.3 to 1.12.

The product is mixed with different molar ratios of aluminum sulfate, sodium silicate, and sodium aluminate, the mixture is mixed at high shear at 10-20 ° C. and the resulting mixture aged at 20-90 ° C. until it becomes a clear solution. Are manufactured.

Although less efficient, PASS is 1.5 to 1.6 times more expensive than aluminum sulfate compared to the production of aluminum sulfate having the same properties and field of use.

Therefore, in view of the positive effects and high cost of PASS, there is a need for agglomerated chemicals that can be obtained with superior or similar, cheaper and simpler manufacturing methods than PASS. The use of high shear mixing means higher investment costs and reduced capacity.

According to the invention the solid zeolite is dissolved in a trivalent metal salt solution in a molar ratio of at least 2: 1, in particular 2-500: 1.

Another feature is as shown in the claims.

Other processes of the present invention can be run at room temperature (20 ° C.) and provide a flocculant of improved properties over other known flocculants based on PASS and trivalent metal salts.

In the present invention, aluminum sulfate, aluminum chloride, polyaluminum hydroxy chloride, polyaluminum hydroxy sulfatochloride, polyaluminum hydroxy sulfate, ferric chloride and a mixture of these salts such as aluminum iron (III) sulfate are bauxite It can manufacture from ore.

Zeolite means a zeolite prepared synthetically with a naturally produced zeolite. The zeolite is sodium aluminum silicate, of which the A-form of the following general formula is preferred.

Na ₁₂ ｜ (AlO ₂ ) ₁₂ (SiO ₂ ) ₁₂ ｜ X27H ₂ O

It contains 14.8% Al, 12.6% Na and 15.3% Si.

The present invention provides a product that is easier to manufacture than known methods, reduces manufacturing costs and also has a Me ³⁺ : Si ratio equivalent to known products, and improves treated water cleaning operations.

The invention is described in more detail in the following examples without being limited thereto.

[Test 1]

1) PASS (OH: AL 1.5: 1) and

2) Aggregate wastewater using a solution of polyaluminum hydroxy sulfate (6.2% Al content, OH: Al 1.5: 1) in which zeolite is dissolved in a weight ratio of 10: 1 (polyaluminum hydroxy sulfate: zeolite).

Turbidity is measured after flocculation sedimentation. Turbidity is measured by breaking up the aggregates with vigorous stirring and precipitating again.

Method: The coagulant was mixed for 10 seconds at a speed of 400 rpm in a coagulator having six agitators, and then coagulated for 10 minutes at a speed of 50 rpm, the precipitate was settled for 10 minutes, the FTU (turbidity) measurement and the analysis of P (phosphorus), and the dissolution for 20 seconds, 10 Settle for minutes and measure the FTU.

The results obtained can be seen in Table 1. Significantly lower turbidity can be obtained using the present invention and thus the aggregates obtained are significantly harder. Moreover, phosphate reduction is large.

TABLE 1

* Values in parentheses are turbidity after disintegration of aggregates. Untreated wastewater is P-tot 8 mg / 1, FTU> 75.

[Test 2]

1) Polyaluminium hydroxy chloride solution (PAK) (OH: Al 1.22: 1) and 2) 1) 0.35 g (ZEO 35), 2 g (ZEO 200) and 10 g (ZEO 1000) zeolite per 100 g solution The wastewater is coagulated using the prepared polyaluminum hydroxy chloride solution.

The turbidity is measured after flocculation and precipitation. Dissolve the aggregates with vigorous stirring and reprecipitate again to measure the turbidity.

Method: The coagulant was mixed at 400 rpm for 10 seconds in a coagulator having 6 stirrers, and again coagulated for 10 minutes at 50 rpm stirring speed, precipitated for 10 minutes, FTU (turbidity) measurement and P (phosphorus) analysis and dismantled for 20 seconds, Allow 10 minutes to settle and measure FTU.

The results obtained can be seen in Table 1. A significantly lower turbidity is obtained according to the invention and thus the aggregates obtained are hard.

TABLE 2

* Values in parentheses are the turbidity after disintegration of aggregates.

[Test 3]

In this test, the effects on the river water of pH 6.9 and turbidity of 1.7 to 3.2 FTU were investigated: zeolite-containing polyaluminum hydroxy chloride (OH: Al 1.22: 1) (PACZEO35, PACZE 200), zeolite-containing aluminum chloride (ACZE035, ACZE200 ), Zeolite-containing aluminum sulfate (ASZE035, ACZE1000), zeolite-containing aluminum sulfate (AVRZE035, AVRZE1000) and zeolite-containing iron (III) sulfate-chlorite (Fe: Cl: SO ₄ 1: 1: 1) (FeZEO 35 , FeZE 100). As a comparative example, a solution of metal salts (PAC, AC, AS, AVR and Fe) is used without addition of zeolite. The test is carried out using 150 μmol Me ³⁺ / 1.

No aggregate disaster is implemented. Others follow the method of test 1 and 2. The results of three replicates are shown in Table 3 below.

TABLE 3

Zeolite Wassalight 90-95 is used (15% Al, 13% Na, 15% Si, LOI (1100 ° C.) 20.8%).

EXAMPLE

The following coagulant is prepared according to the present invention as shown in Table 4. A product is prepared by preparing a metal salt solution in which zeolite is dissolved at 20 ° C.

TABLE 4

* AVR is a product made from bauxite, which is a mixture of Al ₂ (SO ₄ ) ₃ and Fe ₂ (SO ₄ ) ₃ .

The maximum Me ³⁺ concentration in the solution containing Si slightly exceeds that shown in Table 4. However, the aluminum content of the weakly basic polyaluminum chloride solution is as high as 9.5%. If the silicate content is much higher than shown in the table, this solution becomes unstable.

In wastewater flocculation, the product according to the invention is suitably used in an amount of 100 micromoles of Me ³⁺ per liter of wastewater. About 75 micromoles of Me ³⁺ / 1 is used in refining drinking water. In organic material dewatering and sludge dewatering, 300 micromoles of Me ³⁺ / 1 are used. For paper pulp production this concentration is possible at 100 micromolar Me ³⁺ / 1.

Claims (4)

In the method of preparing a flocculant containing a metal salt and a silicate as a flocculant for wastewater refiner, pulp and paper manufacturing, organic material dehydration and inorganic concentration, solid zeolite is added to a trivalent metal salt solution selected from trivalent aluminum salt and trivalent iron salt. Dissolving at a Me ³⁺ : Si molar ratio of -500: 1 to form a reaction product. The solid zeolite of claim 1, wherein the solid zeolite is dissolved in a polyaluminum hydroxy chloride Al (OH) × Cly solution at an Al: Si molar ratio of 2-500: 1 and x is 0.5 to 2.5 and y is 2.5 to 0.5 and x + y. The manufacturing method characterized in that = 3. The solid zeolite of claim 1, wherein the solid zeolite is dissolved in a polyaluminum hydroxy sulfate Al (OH) _a (SO ₄ ) _b solution at an Al: Si molar ratio of 3-500: 1 so that a is 0.5 to 1.8 and b is 0.6 To 1.25 and a + 2b = 3. When the solid zeolite is dissolved in a metal salt solution selected from trivalent aluminum salts and trivalent iron salts in a Me ³⁺ : Si molar ratio of 2-500: 1 in water, cellulose fiber agglomeration, organic material dehydration and inorganic concentration coagulant. Flocculant comprising the reaction product formed.