CN1024272C - Alkaline dregs and powder coal ash bricks exempted from firing - Google Patents

Abstract

The phenomenon that the waste slag discharged from an alkali preparing process comprises fly ash and caustic sludge which are respectively about 10% and 40% of sodium carbonate yield, and severely pollute environment restricts the industrial development. At present, no report shows that a method for effectively utilizing the caustic sludge and for simultaneously utilizing the caustic sludge, the fly ash, etc. for manufacturing baking-free bricks exists at home and abroad. The good performance baking-free brick whose strength exceeds 10MPa is manufactured by the formulation and the technological process of the present invention.

Description

Alkaline dregs and powder coal ash bricks exempted from firing

The present invention makes non-burning brick novel method with alkaline residue.

At present, building brick mostly is clay brick, and energy consumption is big, cost height, waste soil.And coal ash baking-free brick has been owing to utilized power industry waste residue-flyash, and substitute for clay is protected farmland, and has the low characteristics of cost, thereby comes into one's own.

Discharge a large amount of distillation waste residue-alkaline residues in the solvay soda process alkali producing process, account for 40% of soda ash output.In addition, also discharge the flyash that is equivalent to soda ash output about 10%, serious environment pollution, the development of restriction basic industry for guaranteeing supply of electric power.It is non-burning brick to utilize so a large amount of waste residues to make, and not only can administer environment, also can obtain good benefit.At present, still there is not the technology report that utilizes the alkaline residue manufacturing non-burning brick both at home and abroad.

The objective of the invention is on the basis of coal ash baking-free brick, to utilize alkaline residue to make non-burning brick novel method,, reach energy-saving and cost-reducing, the purpose of curbing environmental pollution to obtain the alkaline dregs and powder coal ash bricks exempted from firing that cost is low, performance is good as a kind of important component developing material.

Alkaline dregs and powder coal ash bricks exempted from firing mainly gets by constituent materials such as alkaline residue, flyash and compound activator and water uniform mixing, compression moulding and through suitable maintenance.Also can in batching, mix slag, hardening accelerator and aggregate etc. in case of necessity.

Alkaline dregs and powder coal ash bricks exempted from firing composed as follows:

Alkaline residue: 20-40Wt%;

Flyash: 25-70Wt%;

Slag: 0-40Wt%;

Compound activator: 10-20Wt%;

Aggregate: the 0-22Wt% that accounts for above-mentioned compound total amount;

Water: the 16-20Wt% that accounts for total solids;

Wherein, flyash is pozzolanic materials, can issue living pozzolanic reaction exciting of alkali and vitriol, generates the hydrated product with intensity.

Ca(OH in the alkaline residue) ₂And CaSO ₄Can above-mentioned effect take place with flyash, promote the development of intensity, and the muriate that wherein contains can be got up early and pretended usefulness.

Slag is a kind of low-quality portland cement clinker, can increase the Cao content in the batching, produces pectisation after its aquation, improves non-burning brick intensity, and can improve weather resistance such as its anti-carbonation properties.

The alkali one vitriol compound activator that compound activator is made of by a certain percentage lime and gypsum, its proportion of composing is generally lime: gypsum=2: 1-8: 1.Compound activator has the catalysed promoted effect to the pozzolanic reaction of flyash.

Hardening accelerator: can promote the development of early strength as alkali-metal muriate, oxyhydroxide, vitriol, carbonate, sulfide, short-term strength cement and spent pulping liquor etc.

Aggregate: have certain intensity (as sand, rubble, slag and dry slag etc.), size is no more than 10mm.

The adding of water helps the material homodisperse, mixes and stirs, and provides hydration reaction required moisture content.Non-burning brick bad after the compression moulding, intensity can surpass 10MPa after suitable maintenance, and its hydrated product is similar to the hydrated product of portland cement.

Maintenance process divides natural curing (being no less than 15 days), autoclave curing (4-8atm, 160-180 ℃, following maintenance 4-0 hour); Three kinds of methods of vapor cure (90-100 ℃ following constant temperature 6-12 hour);

The unit weight of alkaline dregs and powder coal ash bricks exempted from firing is similar to clay brick, and water-intake rate meets the requirement of building brick less than 24%.

Technology of the present invention is simple, waste residue utilization rate height, less investment, and product cost is low, can economize on resources and the energy, has good environment, society and economic benefit.(performance is shown in table two, table three).

Embodiment:

Various raw materials are mixed (table one) by a certain percentage, and after blunge was even, compression moulding was through suitably obtaining alkaline dregs and powder coal ash bricks exempted from firing after the maintenance.

Sample 12345678

Batching

Alkaline residue, Wt% 40 40 30 30 20 20 40 30

Flyash, Wt% 40 40 40 40 28 68 43 29

Slag, Wt% 00 20 20 40 00 30

Compound activator, Wt% 20 20 10 10 12 12 17 11

Hardening accelerator accounts for above-mentioned total amount Wt% 02220000

Aggregate accounts for above-mentioned compound total amount Wt% 00 22 00000

Water accounts for total solids Wt% 15 15 15 15 15 15 15 15

The intensity of table two, sample (MPa)

Sample conservation system folding strength ultimate compression strength specimen size (mm)

1 natural curing 46 days 2.00 12.11 240 * 115 * 56

2 autoclave curings (8atm180 ℃ 8 hours) 2.43 11.15 24 * 115 * 56

3 natural curings 46 days 2.86 24.11 240 * 115 * 56

4 autoclave curings (8atm180 ℃ 8 hours) 3.84 13.07 240 * 115 * 56

5 90 ℃ are steam-cured 6 hours---21.13 Φ 30 * 27

6 90 ℃ are steam-cured 6 hours---13.93 Φ 30 * 22

The chemical resistance of concrete ability (R=Rc/Ro) of table 3. sample

Sample 6%MgSO ₄Aq 2.5%H ₂SO ₄Aq 1NNaOHaq 15-20%CO ₂Specimen size (mm)

7 1.11 1.03 1.53 1.15 Φ30×22

8 1.13 0.99 1.10 1.04 Φ30×27

Anti-erosion coefficients R=steam-cured back sample is 28 days ultimate compression strength Rc of maintenance and the steam-cured change of 28 days ultimate compression strength Ro of maintenance in wet air afterwards in various media.

Claims (7)

1, a kind of manufacture method of coal ash baking-free brick is characterized in that adopting following raw material to add an amount of water and makes, and said proportioning raw materials comprises:

Alkaline residue: 20-40Wt%;

Flyash: 25-75Wt%;

Slag: 0-4Wt%;

Compound activator: 10-20Wt%;

Wherein said compound activator by lime and gypsum in lime: gypsum=2: 1-8: 1 ratio is formed.

2, according to the process of claim 1 wherein the hardening accelerator that also can comprise 0-2Wt% in the said proportioning raw materials.

3, according to the method for claim 2, wherein said hardening accelerator is selected from alkali-metal muriate, alkali-metal oxyhydroxide, alkali-metal vitriol, alkaline carbonate, alkali metalsulphide, short-term strength cement and spent pulping liquor.

4, according to the method for claim 1 or 2, wherein said proportioning raw materials also comprises aggregate (＜10mm) 0-22Wt%.

5, according to the method for claim 4, aggregate wherein comprises sand, the stone of quenching, slag and dry slag.

6, according to claim 1, one of 2 or 4 method, it is characterized in that steaming maintenance of oxygen vapour or autoclave curing after the moulding.

7, according to claim 1, one of 2 or 4 method, it is characterized in that carrying out natural curing after the moulding.