CN1369455A

CN1369455A - Efficient calcium thioaluminate type bulking agent and its preparing process

Info

Publication number: CN1369455A
Application number: CN 02116312
Authority: CN
Inventors: 陈智丰; 张振秋
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-03-22
Filing date: 2002-03-22
Publication date: 2002-09-18
Anticipated expiration: 2022-03-22
Also published as: CN1285532C

Abstract

An efficient calcium thioaluminate type bulking agent, an improvement on CAS-type one, features that the lime stone, gypsum and bauxite are first calcined in rotary kiln to prepare clinker, which is them mixed with gypsum and ground while lime stone is added to generate CAS-type bulking agent. Its advantages are high performance and low content of alkali.

Description

High-efficient calcium sulfoaluminate type expander and craft

Technical field

The invention belongs to concrete expansion compound and improve design and supporting production technique, particularly to the improvement of calcium sulphoaluminate type swelling agent manufacture craft.

Background technology

The expansion that obtains to a certain degree at the sclerosis initial stage is a kind of important means of improving concrete performance.For this reason, various types of expansive cements and swelling agent are competitively developed in countries in the world.Although there are many chemical substances can cause concrete expansion by corresponding chemical reaction, the swelling agent of the application that enters so far mainly contains three kinds of reactions: the Cao aquation is Ca (OH) ₂, the Mgo aquation is Mg (OH) ₂, generate the aquation calcium sulphoaluminate.Because the unstable of Cao and Mgo itself and expansion process chemical reaction process, at present seldom application promptly no longer use Cao and Mgo and do major ingredient in the swelling agent.Consistently think that the aquation calcium sulphoaluminate will be at present and the expansion sources that mainly can utilize in the future.

Nineteen sixty-five, before day swelling agent of the present invention, expansive cement and self-stressing cement have been invented in the expansion that produces in the process that Russia and the U.S. two countries all form in mudstone by ettringite, are mainly used to produce cement penstock and expansive concrete.The swelling agent that Japan develops and produce calcium sulphoaluminate type (Colcium Sulpho-Aluminat is abbreviated as CSA) and lime type swelling agent to be become in the world the earliest uses state, is still monopolizing the world market at present.Employing electric furnace fusion calcining in Japan's technology, a kind of ratio proportioning that is the raw material preparation in the formation ettringite directly grinds into swelling agent on the selected batching after burning till, and another kind is to be mixed in proportion when grinding after grog and part gypsum are calcined combustion respectively.

Domestic studies have shown that begins the seventies, CAS swelling agent superior performance, but Costco Wholesale is too high, and the furnace melting technique calcining can't be used at home, adopts to be difficult on the low-cost rotary kiln technology realize.The mid-1970s, it is the swelling agent of main component that China has occurred with alunite and anhydrite, though cost is lower, its unstable properties, expansion period is long, the alkali content height, the volume height still has big gap relatively on its performance of CAS swelling agent.

Summary of the invention

The objective of the invention is to provide a kind of technology way that goes out the CAS swelling agent with the rotary kiln for the main technique device fabrication, and to produce with the calcium sulphoaluminate with this processing method be the cement expansive material of expansion sources.

The present invention improves Japanese CAS swelling agent manufacturing technology.Its basic starting point is not reduce raw-material specification of quality, thereby and the route and the mode of change processes significantly reduce production costs.The gypsum a large amount of more than needed that will add in the time of should joining raw material in this process control procedure adds when changing into the finished product grinding.On the one hand can allocate amount of gypsum exactly into, energy consumption and improve production cost when having removed a large amount of gypsum calcination on the other hand again from according to the actual constituent of grog.The present invention conceives and has improved usage ratio of equipment, and actual this method of proof is effective, and the product of being produced is equally matched with the traditional CAS quality product of Japan, but cost obviously reduces.The new processing method that is formed by above key improvements is as follows:

A, what at first carry out is the preparation section of calcium sulphoaluminate grog, and this operation is exactly to finish the calcination process of bauxitic clay, Wingdale and gypsum mixing raw material in rotary kiln or shaft kiln.

B, again with the calcium sulphoaluminate grog that burns till and gypsum raw material once more the proportioning composition powder wear into the swelling agent finished product.Further specify below in conjunction with process flow sheet and the objective of the invention is how to realize.

Description of drawings

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

Wherein 1 represent Wingdale, 2 represent gypsum, and on behalf of bauxitic clay, A, 3 represent proportioning, pulverizing, homogenizing, and B represents calcining in the rotary kiln, and 4 represents gypsum, and C represents and joins through, pulverizing, homogenizing, and 5 represent stockyard.

Embodiment

For realizing purpose of the present invention, this production technique of improving CAS type swelling agent is designed to two main proportioning processes, at first be the raw material that Wingdale, gypsum and aluminium aluminite proportioning become to be put into rotary kiln calcine, the embodiment of its proportioning is as follows: (weight percent)

Embodiment Wingdale gypsum bauxitic clay

1 85 10 5

2 83 2 15

3 70 15 15

4 50 20 30

Prepare after with three kinds of raw material pulverizing by above embodiment, homogenizing is put into the granulated grog that 1200 ℃～1400 ℃ calcined by rotary kiln become to contain calcium sulphoaluminate.

Actual content and the assembly rationally once more of gypsum raw material with calcium sulphoaluminate in the grog also can suitably add Wingdale, and to adjust characteristic, specific embodiment is as follows:

Embodiment calcium sulphoaluminate grog plaster stone lime stone

5 20 60 20

6 45 40 15

7 60 30 10

8 90 10 0

Homogenizing becomes finished product in the pneumatic blending machine by sending into behind the above Example formulations proportioning combined grinding.

For the above raw material of ensuring the quality of products send the content that should guarantee its effective ingredient when getting, reduce the content of oxious component, this is the primary condition that raw material are selected.Wingdale can be chosen lime, calcium oxide or it is a calcareous raw material for the industrial residue of major ingredient on the basis of ensuring the quality of products, can use natural alumina, aluminum oxide or be that industrial residue, the mine tailing of major ingredient comes the substitution of Al alumina to do aluminum raw material with the aluminum oxide, and can substitute gypsum with natural anhydrite, aqueous gypsum or phosphogypsum, fluorgypsum.Yet should guarantee that Cao content should be greater than 53% in the calcareous raw material in the used raw material of preparation calcium sulphoaluminate grog by chemical examination, and SiO ₂Content should be less than 1.5%.Al in the aluminum raw material ₂O ₃Content should be greater than 70%, and SiO ₂Content should be less than 7%, SO in the gypsum material ₃Content is greater than 48%, SiO ₂Content should be less than 2%.

The granularity of raw material pulverizing is between 80～100 orders when preparation calcium sulphoaluminate grog.And the CAS swelling agent granularity that is processed into should surplus be not more than 10% under 120 mesh sieves, and can guarantee that specific surface area is at 250m ²/ kg.

Utilize the made CAS swelling agent of above novel process, come down in the rotary kiln incinerating calcium sulphoaluminate grog and the gypsum raw material mixture of assembly again.Wherein the calcium sulphoaluminate grog is by 50～85% unslaked lime, and 2～10 gypsum and 5～30% Wingdales mix back calcining institute resultant.Get it and 30～90% add in right amount 10～60% plaster stone again and 0%～20% Wingdale is formed CAS type swelling agent product.

The made CAS swelling agent basic raw material of processing method of the present invention is natural alumina, gypsum and Wingdale, in the alumina in the special place of production, contain the small amount of potassium sodium, substantially do not contain potassium sodium in gypsum and the Wingdale, so alkali content can effectively be controlled at below 0.3% in the swelling agent, content of magnesia also is not more than 3%, and its addition content of evidence is few, the phase of expansion is short, particularly it adopts calcined by rotary kiln, and cost obviously reduces, and performance can be than U.S. with the electric furnace smelting process.It is a significant improvement to existing technology.

Claims

1, efficient calcium sulphoaluminate type swelling agent production technique comprises in the technology that with bauxitic clay, Wingdale, gypsum be the course of processing that raw material is sintered into the sulfur-bearing calcium aluminate clinker, it is characterized in that:

A, above calcination process carry out in rotary kiln or shaft kiln,

B, will calcine the calcium sulphoaluminate grog that generates and generate calcium sulphoaluminate type swelling agent finished product with plaster stone proportioning grinding again.

2, according to the said swelling agent production technique of claim 1, it is characterized in that:

The heavy per-cent of the material component in a, the calcination process is:

Lime 50～85%

Bauxitic clay 5～30%

Gypsum 2～20%

B, the rotary kiln of putting into 1200 ℃～1400 ℃ after the above raw material pulverizing homogenizing is burnt till the calcium sulphoaluminate grog.

3, according to the said swelling agent production technique of claim 1, it is characterized in that with calcium sulphoaluminate grog and plaster stone after the calcining again after the proportioning weight percentages of proportioning again in the operation of grinding generation swelling agent as follows:

Calcium sulphoaluminate grog 20%～90%

Plaster stone 10%～60%

Wingdale 0%～20%

Become powder by above mixed and grinding, send into pneumatic blending machine uniform mixing again.

4, according to the said swelling agent complete processing of claim 2, it is characterized in that: Wingdale can also be selected lime, calcium oxide for use or be that the waste residue of major ingredient substitutes with it, aluminium aluminite can also adopt aluminum oxide or be rich in the waste residue of aluminum oxide or mine tailing substitutes, and gypsum can also use the plaster of paris, aqueous gypsum, phosphogypsum or fluorgypsum alternative.

5,, it is characterized in that in the raw material of preparation calcium sulphoaluminate grog, containing Cao greater than 53%, Sio in the calcareous material according to the complete processing of claim 3 or 4 said swelling agents ₂Less than 1.5%, contain Al in the alumina ₂O ₃Should be greater than 70%, Sio ₂Less than 7%, contain SO in the gypsum ₃Should be greater than 48%, Sio ₂Content is less than 2%.

6,, it is characterized in that preparing in the proportioning raw materials of sulfur-bearing calcium aluminate clinker each raw material grinding particle size at 80～100 orders according to the said swelling agent production technique of claim 1.

7, a kind of calcium sulphoaluminate type swelling agent, comprise sulfur-bearing calcium aluminate clinker and gypsum in its component as expansion sources, it is characterized in that described sulfur-bearing calcium aluminate clinker is by 50～85% Wingdale, what calcining made in 1200 ℃～1400 ℃ rotary kilns behind 5～30% aluminium vanadine and pulverizing of 2～20% gypsum and the uniform mixing, the component weight ratio of swelling agent is:

Calcium sulphoaluminate grog: 30～90%

Gypsum: 10～70%

Unslaked lime: 0～20%

8, according to the said swelling agent of claim 7, it is characterized in that the granularity of swelling agent is not more than 10% in 120 mesh sieve surpluses, specific surface area is not less than 250m ²/ kg.