CN1189414C - High-S silicate cement and its preparing process - Google Patents

Abstract

The present invention relates to high sulfur Portland cement, oxide in clinker of the cement comprises 1.5% to 3.0% of SO3 and 63% to 68% of CaO, and the clinker has 2.6% to 5.1% of CaSO4. Four rate values in a clinker calcination process are respectively controlled in the following ranges: KH is controlled from 0, 92 to 1.00, n is controlled from 1.9 to 2.5, p is controlled from 1.00 to 1.80, S^R is controlled from 0.18 to 0.32, wherein the S^R is the left top formula, MgO is controlled from 0.5 to 2.0%, and the calcining temperature is controlled from 1350 to 1400 DEG C. In the production process of the high sulfur Portland cement, gypsum does not need to be added, and less poisonous exhaust gas is discharged. The present invention has high strength, better performance, reduced production cost, easy implementation and environmental protection.

Description

High-sulphur Portland cement and production method thereof

Technical field

The invention belongs to the cement technology field.

Background technology

Silicate cement is used widely in construction work, and also there has been the national standard of oneself in China.Sulfur trioxide content to grog in standard does not have concrete regulation, is generally about 1%, is 1.2～1.3% to the maximum.Standard has also been stipulated must add gypsum when clinker grinding, to guarantee its delayed coagulation.Also early existing people finds: sulfur trioxide content helps slow setting in the raising cement clinker, and some factories have taked to fire with high sulphur coal the method for grog, in the hope of reaching the purpose that strengthens sulfur trioxide content in the grog, but when adopting this method, the sulphur considerable part becomes a component of fluorine sulphur composite mineralizer in the coal, in grog, form sulplo-aluminate and fluorosulfuric acid salt at last, and the amount of formation calcium sulfate is less, causes cement clinker undesired time of coagulation.Simultaneously, the coal in the raw material at first will satisfy fires the required hear rate of grog, and it but is accessory forming calcium sulfate, causes to generate calcium sulfate amount instability in the grog, does not reach and gives the phase requirement, also discharges more sulfurous gas, contaminate environment during calcining.The inventor once delivered on the second phase in 1999 at " cement " magazine＜and add the experimental study that citric acid waste is fired the high-sulfur cement clinker in the raw material〉literary composition, introduction uses citric acid waste to fire the high-sulfur cement clinker, wherein mentions this composition of testing used citric acid waste and is: %:SiO ₂0.41, Al ₂O ₃0.27, Fe ₂O ₃0.12 CaO 31.99, MgO 0.24, and SO 46.00.Test-results shows: add citric acid waste in the raw material and can make CaCO ₃Decompose in advance, reduce the grog liquid phase and temperature occurs, improve the grog performance, reduce production costs, but unexposed key process parameter.

Summary of the invention

The technical problem to be solved in the present invention is to improve sulfur trioxide content in the Portland clinker, no longer adds gypsum during preparation cement.

The present invention solves the problems of the technologies described above with following technical scheme: sulphur trioxide 1.5～3.0% is arranged in the oxide compound of high-sulphur Portland cement grog, and CaO 63～68%, CaSO in the mineralogical composition ₄Be 2.6～5.1%.

The method of production high-sulphur Portland cement is: in whole technological process, four big rate values are controlled at following scope:

Lime saturation factor KH:0.92～1.0

Silicon rate SM (n): 1.90～2.50

Aluminium rate IM (p): 1.0～1.8

Sulphur rate SR 0.18～0.32 $\stackrel{\‾}{S}R=\frac{{\mathrm{SO}}_3}{A{l}_2{O}_3+{\mathrm{Fe}}_2{O}_3}$

Mgo is controlled to be 0.5～2.0%, 1350～1400 ℃ of calcining temperatures

High-sulphur Portland cement of the present invention contains higher vitriol in the grog, time of coagulation is normal, need not add gypsum when its grinding is prepared cement, the cement products label of producing can reach 425～725, and has utilized the waste residue in the citric acid production process, be beneficial to environmental protection, reduced cement cost.

Embodiment

High-sulphur Portland cement of the present invention, the main oxides content range is in its grog: CaO 63～68%; SiO ₂20～24%; Al ₂O ₃3～6%; Fe ₂O ₃2.6～5.0%; SO ₃1.5～3.0%; Corresponding essential mineral composition is tricalcium silicate (3CaOSiO ₂), Dicalcium Phosphate (Feed Grade) (2CaOSiO ₂), tricalcium aluminate (3CaOAl ₂O ₃) tetracalcium aluminoferrite (4CaOAl ₂O ₃Fe ₂O ₃) and calcium sulfate (CaSO ₄).Its physicals is identical with general silicate cement with purposes.

High-sulphur Portland cement production method of the present invention is:

The raw grinding for preparing is in proportion mixed:

Wingdale 78～80% (mass percent, as follows)

Clay 8～14%

Iron ore 4～7%

Citric acid waste 4～6%

Grinding fineness is controlled at 7～10% (tailing over), is sintered into cement clinker again in cement kiln, if use the shaft kiln calcination mixed raw material, also will allocate coal in raw material balling-up according to the grog energy consumption, is transported in the shaft kiln and burns; If use calcined by rotary kiln, can directly be transported to mixed raw material in the kiln, with heavy oil or coal calcination.

Calcining temperature is controlled at 1350～1400 ℃ of scopes, and in process of production, best lime saturation factor KH value is controlled at 0.92～1.00, silicon rate SM (n) is controlled at 1.9～2.50, and aluminium rate IM (p) is controlled at 1.00～1.80, and sulphur rate SR is controlled at 0.18～0.32, MgO is controlled at 0.5～2.0%

Sulphur rate SR is defined as $\frac{{\mathrm{SO}}_3}{{\mathrm{Al}}_2{O}_3+{\mathrm{Fe}}_2{O}_3}$

Alkali total amount K _AlwaysBe controlled at 0.25～1.00%

Burn till grog and put into grinding machine and wear into finished cement, can add blended material in the grinding to make different varieties cement.The a few types gypsum is arranged in the citric acid waste, and after the mineralization, the grog calcium sulfate of Xing Chenging has delayed coagulation again simultaneously.Owing to utilized " two agent effect " of citric acid waste, improved the burn-ability of raw material, reduced the decomposition temperature and the liquid phase viscosity of lime carbonate, increase amount of liquid phase, calcining temperature can be reduced to below 1400 ℃, and has promoted the especially formation in A ore deposit of silicate minerals, has improved the intensity of cement clinker.The grog calcium sulfate that forms after the mineralization has delayed coagulation, makes grog normal time of coagulation, must not add gypsum when grinding cement, and the amount of sulfur dioxide of discharging in the calcination process is less, even can reach zero release.

Below be three specific embodiments:

Each embodiment all carries out in the laboratory.Add water 10% (quality %) to mixed raw material and be shaped to ￠ 30 * 5mm small cake, put into the retort furnace calcining.Raw material is taken from factory.The test of using and the instrument of detection method and use are undertaken by the GB requirement.The calcining temperature of each sample is respectively at 1350 ℃, 1380 ℃, 1400 ℃.

Table 1 three mixed raw material samples chemical ingredients and rate value

Numbering	Chemical ingredients/%								The rate value
												Loss	SiO 2	Al 2O 3	Fe 2O 3	CaO	MgO	SO 3	∑	KH	n	p
	1	34.10	13.85	3.35	2.28	43.23	0.56	1.90	99.27	0.952	2.46												1.47
2												34.84	13.69	3.01	2.15	43.43	0.48	2.28	99.88	0.984	2.65	1.40
	3	35.12	12.63	2.98	2.16	43.21	0.91	2.26	99.27	1.06	2.46												1.38

Annotate: the Loss-loss on ignition

Corresponding grog chemical ingredients of table 2 and rate value

Numbering	Chemical ingredients/%									The rate value				Vso 3 /％
															Loss	SiO 2	Al 2O 3	Fe 2O 3	CaO	MgO	SO 3	f-c	∑	KH	n	p	SR
	1	2.92	20.31	5.10	3.91	63.74	0.84	2.92	4.39	99.84	0.949	2.25	1.30															0.32	Do not detect
2														3.14	20.34	4.66	3.86	64.56	0.87	2.16	1.04	99.59	0.975	2.39	1.21	0.25	38.1
	3	1.56	19.85	5.18	3.40	65.84	1.37	2.72	1.80	99.92	0.943	2.31	1.52															0.31	21.9

Annotate: f-c one free CaO Vso ₃-SO ₃Volatile quantity

The corresponding grog physicals of table 3

Claims (3)

1, a kind of high-sulphur Portland cement, in the oxide compound of its grog, major ingredient is CaO, SO ₃, SiO ₂, Al ₂O ₃, Fe ₂O ₃, MgO, when representing each composition with mass percent, SiO wherein ₂Be 20～24%, Al ₂O ₃Be 3～6%, Fe ₂O ₃Be 2.5～5.0%, SO ₃Be 1.5～3.0%, CaO is 63～68%, and MgO is 0.5～2.0%.

2, a kind of method of producing high-sulphur Portland cement as claimed in claim 1, with mature calcined material behind the raw grinding, grinding becomes cement again, it is characterized in that:

The mass percent of each component is in the raw material: contain citric acid waste and be 4～6%, Wingdale is 78～80%, clay is 8～14%, iron ore is 4～7%;

In the whole technological process four big rate values are controlled at following scope:

Lime saturation factor KH:0.92～1.0

Silicon rate SM (n): 1.90～2.50

Aluminium rate IM (p): 1.0～1.8

Sulphur rate SR:0.18～0.32

Wherein: $\stackrel{\‾}{S}R=\frac{{\mathrm{SO}}_3}{{\mathrm{Al}}_2{O}_3+{\mathrm{FeO}}_3}$

1350～1400 ℃ of calcining temperatures.

3, the production method of high-sulphur Portland cement as claimed in claim 2 is characterized in that alkali total amount K _AlwaysValue is controlled at 0.25～1.00%.