CN1046257C

CN1046257C - Wet process for producing flyash cement

Info

Publication number: CN1046257C
Application number: CN94116979A
Authority: CN
Inventors: 宋存义; 倪文; 郑玉春; 梁军; 刘凤梅
Original assignee: University of Science and Technology Beijing USTB
Current assignee: University of Science and Technology Beijing USTB
Priority date: 1994-10-21
Filing date: 1994-10-21
Publication date: 1999-11-10
Anticipated expiration: 2014-10-21
Also published as: CN1121057A

Abstract

The present invention discloses a production technology for producing low-grade fly ash cement for construction by using a wet method. The drying working procedures of fly ash are cancelled, and a gelled material which has favorable performance and low cost and can be singly used as low-grade cement and can be directly produced by using wet fly ash. The production technology is characterized in that 1 to 5% of semi-hydrated gypsum (CaSO4*1/2H2O) is added on the basis of dual fly ash, and the water in the wet fly ash is dried in a pre-balancing reservoir by using the hygroscopic effect and the exothermic effect of calcium oxide in a pre-balancing reservoir. The product produced by the method has the advantages of good stability, high strength, much dust absorption and low cost.

Description

The method of pre-homogenizing wet process for producing flyash cement

The present invention relates to a kind of production method of low grade pulverized fuel ash cement for building.

The method of producing analogous products in the prior art generally has two kinds, and a kind of is to make " Shuanghui powder " in proportion with original state dry powder coal ash and unslaked lime, is used for mortar instead of part cement and lime, and itself can not use as cement separately; Another kind is the slag-fly ash clinker-free cement, be subjected to the restriction in slag source.These two kinds of method common shortcomings are must be in advance through oven dry, and it is levigate just to enter grinding machine, has so just increased cost greatly.

The objective of the invention is to cancel the baking operation of flyash, utilize the wet fly-ash direct production to go out the gelling material that performance is good, cost is low, can use as cement of low index separately.

The present invention is on the basis of existing procucts " Shuanghui powder ", utilizes the moisture absorption and the pyrogenic effect of unslaked lime, adopts pre-homogenizing process, makes the moisture mummification in pre-homogenization process in the wet fly-ash, and its technical process is as follows:

The invention is characterized in to be provided with pre-balancing reservoir in the production technique, in the former ratio of components (by weight) require unslaked lime 20-50%, flyash 50-80% has added the semi-hydrated gypsum (CaSO of 1-5% ₄1/2H ₂O).Carry out levigate after each component mixes.

Ingredient requirement unslaked lime of the present invention should burn till at 1030-1170 ℃, and CaO content is (by weight) 80%-99%, and the flyash water ratio is (by weight) 5-30%, and carbon content rate is (by weight) 2-8%.

Fine grinding process adopts Raymond mill formula or steel ball grinder, and product fineness is 0.10-0.001mm, and the granularity after the unslaked lime fragmentation is 5-45mm.

The pre-homogenizing time is 16-30 hour, and the best pre-homogenizing time is 24 hours, and pre-homogenization temperature is 0-150 ℃.

The invention has the advantages that technology is simple, with low cost; Compare with the Portland cement production technique and to have save raw material preparation and grog firing process, compare, save the heating, drying operation, reduced dust work, improve work situation with dry production flyash.Low grade pulverized fuel ash cement with this law production, good security, intensity height, eat ash many, both can be added in the normal concrete and to improve early strength or to do the gelling material use separately, can make building block, no grog gas concrete piece, baking-free lightweight brick etc. again, good economic benefit is arranged.

Subordinate list 1 adopts the mortar and the performance thereof of No. 75 pulverized fuel ash cement preparations.

Mortar design label	Low grade pulverized fuel ash cement week measures	Mix the sand amount	The silicate cement consumption	Denseness	Delamination degree	Ultimate compression strength (Mpa)
						Ultimate compression strength (Mpa)			7 days	28 days	90 days
						25	1	5.5	7 days	28 days	90 days	0	7	2.1	1.3	2.7	5.1
50	1	8	0.7	6.7	2.7	25	1	5.5	3.2	5.8	7.8	0	7	2.1	1.3	2.7	5.1
50	1	8	0.7	6.7	2.7	75	1	14	3.2	5.8	7.8	1.6	7.0	2.6	6.2	8.2	12.1

(measuring) by Hebei province's construction engineering quality inspection center

By the table in as seen, when mortar mark is No. 25, can save silicate cement fully.When design label when being No. 50 and No. 75, can add small amounts of silicate cement and regulate.When the cement of low index that adopted this during as No. 175, can save the mortar that silicate cement is prepared various labels fully.

Claims

1. the production method of a low grade pulverized fuel ash cement is characterized in that being provided with in the production technique pre-balancing reservoir, and proportioning raw materials (by weight) is unslaked lime 20-50%, and flyash 50-80% adds the 1-5% semi-hydrated gypsum, carries out levigate after each component mixes.

2. production method as claimed in claim 1 is characterized in that unslaked lime should burn till at 1030-1170 ℃, and CaO content is (by weight) 80-99%, and the flyash water ratio is (by weight) 5-30%, contains the charcoal rate and is (by weight) 2-8%.

3. production method as claimed in claim 1 is characterized in that fine grinding process adopts Raymond mill or steel ball grinder, and the fineness of product is 0.10-0.001mm.

4. production method as claimed in claim 1 is characterized in that the pre-homogenizing time is 16-30 hour, and pre-homogenization temperature is 0-150 ℃.