CN1249285A

CN1249285A - Synthetic compact aggregate of aluminium silicate and its preparing process

Info

Publication number: CN1249285A
Application number: CN 98110482
Authority: CN
Inventors: 董文君; 曹继昌; 张兆平; 陈锡鲁
Original assignee: WANGCUN BAUXITE MINE SHANDONG PROV
Current assignee: WANGCUN BAUXITE MINE SHANDONG PROV
Priority date: 1998-09-28
Filing date: 1998-09-28
Publication date: 2000-04-05
Anticipated expiration: 2018-09-28
Also published as: CN1061957C

Abstract

A new-type refractory aluminium silicate aggregate and its preparing process are disclosed. Said aggregate contains SiO2 and Al2O3 (40-60 wt.%). Its mineral components mainly are mullite phase and high-Si-O glass phase. Its advantages are high high-temp chemical and volume stabilities, higher volume density and specific weight, and low porosity and water absorption. The refractory products made of said aggregate have high heat shock stability, high anti-strip power and long service life.

Description

Synthetic compact aggregate of aluminium silicate and preparation method thereof

The present invention relates to a kind of novel pure aluminium silicate refractory aggregate and preparation method thereof, belong to fire resisting material field.

At present, Al ₂O ₃Content is at 40～60% " SiO ₂～Al ₂O ₃" be that refractory aggregate mainly comprises hard paste grog and three grades of bauxite chamottes, its main crystalline phase consists of mullite, cristobalite, glassy phase, also contains the unsetting SiO of part ₂With unsetting Al ₂O ₃, cristobalite wherein, glassy phase and unsetting SiO ₂, unsetting Al ₂O ₃Performance to grog plays a part harmful.Such grog adopts the method that is prepared as follows: through washing, selection, screening, the bulk material that will have the certain particle size scope is again calcined directly into kiln with its raw ore, and calcining temperature is generally 1250～1400 ℃.Therefore, there are following shortcoming in common refractory aggregate and preparation method:

(1) calcining temperature is low.Because raw ore has only carried out simple washing, selection and screening, just calcine directly into kiln, its calcining temperature depends primarily on the sintering characteristic of raw ore self, and be generally a certain little temperature range in 1250～1400 ℃ of scopes according to the calcining temperature that the raw ore characteristic is determined, what the raw ore sintering carried out under this temperature is not thorough.When calcining temperature surpassed this temperature, product promptly burn-off phenomenon can occur: volume density descends, and void content and water-intake rate improve.

(2) because calcining temperature is low, the mineral composition content of the actual generation of product does not reach theoretical value.For example: Al ₂O ₃Content is about 45% hard paste grog, and calcining heat is 1250 ℃ ± 20 ℃, and the actual mullite that generates accounts for about 25% (theoretical value is 55～65%), and the actual cristobalite that generates accounts for about 23% (theoretical value is about 40%).Because it is not thorough that sintering carries out, and also contains a large amount of unsetting SiO in the product ₂With unsetting Al ₂O ₃, the secondary mullite reaction at high temperature will take place and follow bigger Volume Changes in the refractory product made from it, thereby reduce yield rate, serviceability temperature and the service life of refractory product.

(3) contain the cristobalite phase, Al in the grog aggregate ₂O ₃Content is 40～60% the time, resistant mineral wherein is mullite, cristobalite and glassy phase, under different temperature, hocketing transformation of crystal and follow bigger bulk effect of cristobalite, thereby the existence of cristobalite has reduced the heat of refractory product and has shaken stability, spalling resistance and service life.

The object of the present invention is to provide a kind of pure aluminium silicate refractory aggregate of new composition, this aggregate has stability at elevated temperature and high volume stability preferably, higher volume density and true specific gravity, lower void content and water-intake rate, the refractory product heat made from this aggregate good stability that shakes, the antistripping ability is strong, long service life.The present invention also provides its preparation method simple, that easily go.

Described novel alumina silicate refractory aggregate is synthetic compact aggregate of aluminium silicate, contains SiO ₂, Al ₂O ₃, Al ₂O ₃Content be its mineral composition of 40～60%wt be mainly mullite mutually with vagcor mutually.

Wherein, mullite is 55～85%wt mutually, and cristobalite is a small amount of or trace or do not contain mutually, and surplus is the vagcor phase.The technical indicator of aggregate is: volume density 〉=2.63g/cm ³, void content≤2%.

Preparation method's technology of this refractory aggregate is simple, implements easily, and is specific as follows:

Comprise that common raw material selects materials, pulverizes and calcine, its main technical points is that raw meal was broken to 200 mesh sieves, the most well 400 mesh sieves.

The selection of raw material requires with common the same, according to Al in the grog aggregate ₂O ₃Content requirement and decide, if single raw material can meet the demands, can use single raw material, if single raw material can not meet the demands, then according to Al ₂O ₃Content requirement calculate the cooperation consumption of used several raw materials, the present invention is raw materials used can be the single raw material of flint clay, the main chemical composition of flint clay is SiO ₂38～50%, Al ₂O ₃41～48%.Single raw material, so that technology is simpler, easily operation, cost is low.If processing condition allow, raw material pulverizing is thin more good more.

Adopt aforesaid operations to carry out the preparation of refractory aggregate, the calcining temperature of raw material can be controlled in 1400～1650 ℃ of scopes, and burn-off phenomenon can not occur.Al in the grog ₂O ₃The height of content is determining the height of calcining heat, usually, and Al ₂O ₃Content height, calcining heat are just high, Al ₂O ₃Content is low, and calcining heat is just low.But, the raw material that adopts art breading of the present invention to cross, very big variation has taken place in its sintering characteristic, susceptibility to the sintering temperature height has reduced, the calcining scope of raw material is widened greatly, realize to make raw material at heat preservation sintering of following short period of time of comparatively high temps, also can make the long-time at a lower temperature heat preservation sintering of raw material, avoided burn-off phenomenon.

In described preparation method, the pulverizing of raw material adopts the wet ball grinding method better, the efficient height, again can be directly with the ball milling material behind dehydration, vacuum pugging, make clod, carry out drying, calcining.

Preparation technology's of the present invention enforcement can make the mullite synthesizing crystalline phase reach theoretical value basically, and makes deleterious cristobalite most of mutually or all changed into glassy phase.In calcination process, mullite has at high temperature formed " needle-like crossover network skeleton ", has high viscosity, low-expansion glassy phase filling in the gap, has finally formed mullite--the vagcor composite diphase material.This material has preferably stability at elevated temperature and high volume stability, higher bulk density and true specific gravity, and the lower porosity and water absorption rate, the refractory product heat made from this material good stability that shakes, the anti-strip ability is strong, long service life.

The improvement that the present invention carries out is so that the preparation technology of refractory aggregate becomes simply, easy row, and can adjust flexibly, and the refractory aggregate that makes forms stable, dependable performance.

The sample 1 of refractory aggregate of the present invention and sample 2 detect through Shandong Province's construction sanitary ceramic and non-metallic mineral products quality monitoring testing station, its assay sees Table 1, its X-ray diffraction detects collection of illustrative plates and sees Fig. 1 and Fig. 2, atlas analysis shows, principal crystalline phase in this refractory aggregate is a mullite, and other is less.

Table 1: assay

	The quality index title	Measure unit	Assay
			Assay		Monodrome	Mean value
			Sample one	Loss on ignition	Monodrome	Mean value	????％	????0.32
????S _iO ₂	????％	????47.31		Loss on ignition			????％	????0.32
????S _iO ₂	????％	????47.31		????F _e2O ₃		????％	????1.38
????Al ₂O ₃	????％	????48.71		????F _e2O ₃		????％	????1.38
????Al ₂O ₃	????％	????48.71		????T _iO ₂		????％	????0.68
????C _aO	????％	????0.25		????T _iO ₂		????％	????0.68
????C _aO	????％	????0.25		????M _gO		????％	????0.15
????K ₂O	????％	????0.19		????M _gO		????％	????0.15
????K ₂O	????％	????0.19		????N _a2O		????％	????0.33
Apparent porosity	????％	????1.7，1.8		????N _a2O	??1.8	????％	????0.33
Apparent porosity	????％	????1.7，1.8		Volume density	??1.8	????g/cm ³	????2.57，2.57	??2.57
True density	????g/cm ³	????2.76，2.76?2.72		Volume density	??2.74	????g/cm ³	????2.57，2.57	??2.57
True density	????g/cm ³	????2.76，2.76?2.72		Sample two	??2.74	Apparent porosity	????％	????0.6，0.7，0.7	??0.7
Volume density	????g/cm ³	????2.63，2.63，2.63	??2.63			Apparent porosity	????％	????0.6，0.7，0.7	??0.7
Volume density	????g/cm ³	????2.63，2.63，2.63	??2.63		Battle array density	????g/cm ³	????2.86，2.88，2.88	??2.87

The present invention is further illustrated below in conjunction with embodiment.

In following examples, raw material is crossed 200 orders or 400 mesh sieves, and raw material is pulverized the wet ball grinding method of using, and the ball milling material is made clod behind dehydration, vacuum pugging, then dry, calcining.Not elsewhere specified other technological parameter is with reference to the preparation of common refractory aggregate.

Table 2: each embodiment situation table look-up

	Green coke jewel (%wt)	Alumina (%wt)	Al in the aggregate ₂O ₃Content (%wt)	Raw material sieve (order)	Calcinating system	Mullite content (%wt)	Cristobalite content (%wt)	Volume density (g/cm ³)	Void content (%)
	Green coke jewel (%wt)	Alumina (%wt)	Al in the aggregate ₂O ₃Content (%wt)	Raw material sieve (order)	Calcinating system	Mullite content (%wt)	Cristobalite content (%wt)	Volume density (g/cm ³)	Void content (%)	Embodiment 1	??100	??0	????45	??400	1550℃×2h	????62.7	Trace	????2.65	??0.7
Embodiment 2	??96	??4	????47	??400	1550℃×2h	????65.5	Trace	????2.63	??0.9	Embodiment 1	??100	??0	????45	??400	1550℃×2h	????62.7	Trace	????2.65	??0.7
Embodiment 2	??96	??4	????47	??400	1550℃×2h	????65.5	Trace	????2.63	??0.9	Embodiment 3	??65	??35	????60	??400	1650℃×3h	????83.6	Trace	????2.65	??0.8
Embodiment 4	??100	??0	????45	??400	1500℃×2h	????60	Trace	????2.61	??0.8	Embodiment 3	??65	??35	????60	??400	1650℃×3h	????83.6	Trace	????2.65	??0.8
Embodiment 4	??100	??0	????45	??400	1500℃×2h	????60	Trace	????2.61	??0.8	Embodiment 5	??100	??0	????45	??400	1450℃×2h	????57	On a small quantity	????2.59	??0.9
Embodiment 6	??100	??0	????45	??200	1450℃×2h	????59	Trace	????2.65	??0.7	Embodiment 5	??100	??0	????45	??400	1450℃×2h	????57	On a small quantity	????2.59	??0.9
Embodiment 6	??100	??0	????45	??200	1450℃×2h	????59	Trace	????2.65	??0.7	Embodiment 7	??100	??0	????45	??400	1400℃×3h	????56	On a small quantity	????2.57	??0.8
Embodiment 8	??100	??0	????45	??200	1500℃×2h	????60	Trace	????2.62	??0.6	Embodiment 7	??100	??0	????45	??400	1400℃×3h	????56	On a small quantity	????2.57	??0.8
Embodiment 8	??100	??0	????45	??200	1500℃×2h	????60	Trace	????2.62	??0.6	Embodiment 9	??100	??0	????45	??200	1600℃×2h	????57	On a small quantity	????2.63	??0.8

Aggregate appearance color shown in the embodiment 1 is a khaki color, and fracture is a grey, compact structure, and its volume density is 2.65g/cm ³, void content is that 0.6%, 25～1300 ℃ thermal expansivity is 4.2 * 10 ^-6K ^-1

The chemical composition that table 3: embodiment is raw materials used

Chemical composition (%wt)	IL	S _iO ₂	Al ₂O ₃	M _gO	C _aO	KN _aO	T _iO ₂	Fe ₂O ₃
Chemical composition (%wt)	IL	S _iO ₂	Al ₂O ₃	M _gO	C _aO	KN _aO	T _iO ₂	Fe ₂O ₃	The green coke jewel	14.16	44.19	39.07	0.13	0.21	0.29	0.58	1.19
Alumina	14.30	4.99	74.95	0.16	0.13	0.03	1.67	1.06	The green coke jewel	14.16	44.19	39.07	0.13	0.21	0.29	0.58	1.19

With the refractory brick that refractory aggregate of the present invention is made, the heat stability (1100 ℃ of water-cooleds) of shaking reaches 10 times, and the rate of peeling off is zero, and with the refractory brick of common refractory aggregate making, and its heat stability of shaking only is 4 times, and the rate of peeling off is up to 47%.

Claims

1, a kind of synthetic compact aggregate of aluminium silicate contains SiO ₂, Al ₂O ₃, Al ₂O ₃Content be 40～60%wt, it is characterized in that its mineral composition be mainly mullite mutually with vagcor mutually.

2, aggregate according to claim 1 is characterized in that mullite is 55～85%wt mutually, and cristobalite is trace mutually, and surplus is the vagcor phase.

3, aggregate according to claim 1 and 2 is characterized in that its index is volume density 〉=2.63g/cm ³, void content≤2%.

4, the described aggregate processing method of a kind of claim 1 comprises that raw material selects materials, pulverizes and calcine, and it is characterized in that raw material pulverizing is to crossing 200 mesh sieves.

5, preparation method according to claim 4 is characterized in that raw material pulverizing crosses 400 mesh sieves.

6, preparation method according to claim 4, the calcining temperature that it is characterized in that raw material is 1400～1650 ℃.

7, preparation method according to claim 4 is characterized in that raw material adopts the single raw material of flint clay.

8, according to claim 4,5,6,7 described preparation methods, it is characterized in that raw material pulverizing wet ball grinding method.

9, preparation method according to claim 8, it is characterized in that the ball milling material through dehydration, behind the vacuum pugging, make clod, then dry, calcining.