A kind of preparation method of high strength cement
Technical field
The present invention relates to a kind of preparation method of cement, especially relate to a kind of preparation method of high strength cement.
Background technology
China produces more than 500,000,000 ton of cement per year, and 80% is shaft kiln production, and shaft kiln production is limited by processing condition, and the strength of cement that grinds is lower, and quality is lower, can't reach the service requirements in some place.Although existing manufacture of cement has made some improvements, all fundamentally do not solve the quality problems of strength of cement.
At present, new cement national standard is revised and implements, and new national standard carries out ruggedness test according to international ISO method, and because water cement ratio, cement-sand ratio, standard sand etc. change, strength of cement originally will reduce a grade according to new standard.
Some Code in Hazardous Special Locations such as Fang Hai, anti-river levee dam etc., can only use high strength cement, but the cement of traditional gypsum production can not satisfy high-intensity requirement.
In steelmaking process, can produce large steel slag in steel melting furnace, for steelworks, this class material abandons stacking mostly, both land occupation resource, contaminate environment again.
Summary of the invention
The technical problem to be solved in the present invention is, overcomes the deficiencies in the prior art, and a kind of preparation method of high strength cement is provided.
The present invention solve the technical problem the technical scheme that adopts, and comprises the following steps:
(1) with levigating steel slag, grind size is that 0.30mm tails over less than 5%, gets the slag powder;
(2) with the desulfurated plaster dehydration, generate semi-hydrated gypsum;
(3) sandy soil, coal, ferrous ion compound and step (2) gained semi-hydrated gypsum are mixed, get the mixture of sandy soil, coal, ferrous ion compound and semi-hydrated gypsum;
The weight percent of described semi-hydrated gypsum, sandy soil, coal and ferrous ion compound is: semi-hydrated gypsum 75-85%, sandy soil 5-15%, ferrous ion compound 0.5-2%, coal 8-15%;
(4) step (3) gained mixture is joined grind in preheater and grind, grind size is that 0.10mm tails over 15-18%; 0.20mm tail over less than 2%; When grinding, mixture is carried out preheating, preheating temperature is 600-750 ℃;
(5) will add in rotary kiln through the mixture that step (4) is processed and calcine, calcining temperature is 900-1550 ℃ (preferred 1500 ℃), forges to pass into air when watering (flow that preferably passes into air is 1-1.2m
3/ h), get cement clinker and by product sulfur dioxide gas;
(6) step (5) gained cement clinker is cooling, then be slag powder 35-65% with step (1) gained slag powder, desulfurated plaster, step (5) gained cement clinker, sandy soil according to weight percent, desulfurated plaster 15-35%, cement clinker 3-8%, the ratio of sandy soil 10-45% is mixed, stir, namely get high strength cement.
Described ferrous ion compound is iron protoxide (FeO), ferrous hydroxide (Fe (OH)
2), ferrous sulfate (FeSO
4) or iron protochloride (FeCl
2) etc. the compound of ferrous ion.
The preparation method of the present invention's high strength cement effectively utilizes the waste resource of enterprise, has both alleviated the pressure of iron and steel electric power enterprise environmental protection, can solve again the problem of building materials enterprise shortage of resources; The by product sulfur dioxide gas can be used for preparing sulfuric acid.
The preparation method of the present invention's high strength cement, the cement products that makes, intensity is high, has reached the index request of GB13590-2006 " slag silicate cement ", and namely time of coagulation, initial set was not less than 90min, and final set is not more than 600min; Stability is qualified; 3 days ultimate compression strength is more than or equal to 10MPa, and ultimate compression strength was more than or equal to 32.5MPa in 28 days; 3 days folding strengths are more than or equal to 2.5MPa, and 28 days folding strengths are more than or equal to 5.5MPa, and specific surface area is not less than 38m
2/ kg; Contract with dry rate was not more than 0.1% in 28 days.
Embodiment
Below in conjunction with embodiment, the present invention is described in further detail.
Embodiment 1
The present embodiment comprises the following steps:
(1) with levigating steel slag, grind size is that 0.30mm tails over less than 5%, gets the slag powder;
(2) with the desulfurated plaster dehydration, generate semi-hydrated gypsum;
(3) sandy soil, coal, iron protoxide and step (2) gained semi-hydrated gypsum is mixed, get the mixture of sandy soil, coal, ferrous ion compound and semi-hydrated gypsum;
The weight percent of described semi-hydrated gypsum, sandy soil, coal and iron protoxide is: semi-hydrated gypsum 80%, sandy soil 10%, ferrous ion compound 1%, coal 9%;
(4) step (3) gained mixture is joined grind in preheater and grind, grind size is that 0.10mm tails over 15-18%; 0.20mm tail over less than 2%; When grinding, mixture is carried out preheating, preheating temperature is 600 ℃;
(5) will add in rotary kiln through the mixture that step (4) is processed and calcine, calcining temperature is 900 ℃, forges to pass into air when watering (flow that passes into air is 1.0m
3/ h), get cement clinker and sulfur dioxide gas;
(6) step (5) gained cement clinker is cooling, then desulfurated plaster, sandy soil, step (1) gained slag powder and step (5) gained cement clinker are mixed, stir, namely get high strength cement;
The weight percent of step (1) gained slag powder, desulfurated plaster and step (5) gained cement clinker, sandy soil is: slag powder 35%, desulfurated plaster 35%, cement clinker 5%, sandy soil 25%.
The raw material weight proportioning of embodiment 2-4 and preheating temperature, calcining temperature are listed in table 1, and other steps are identical with embodiment 1.
Embodiment 2 ferrous ion compound used is ferrous hydroxide; Embodiment 3 ferrous ion compound used is ferrous sulfate, and embodiment 4 ferrous ion compound used is iron protochloride.
The high strength cement analytical test of embodiment 1-4 preparation the results are shown in Table 2.
Table 1 embodiment 1-4 raw material weight proportioning and Parameter Conditions
Sequence number |
Semi-hydrated gypsum |
Sandy soil |
The ferrous ion compound |
Coal |
Preheating temperature (℃) |
Calcining temperature (℃) |
The slag powder |
Desulfurated plaster |
Cement clinker |
Sandy soil |
Pass into the flow of air |
Embodiment 1 |
80 |
10 |
1 |
9 |
600 |
900 |
35 |
35 |
5 |
25 |
1.0 |
Embodiment 2 |
75 |
15 |
2 |
8 |
700 |
1300 |
65 |
15 |
3 |
17 |
1.1 |
Embodiment 3 |
85 |
5 |
0.5 |
9.5 |
750 |
1200 |
57 |
26 |
7 |
10 |
1.2 |
Embodiment 4 |
78 |
8 |
1 |
13 |
720 |
1550 |
37 |
15 |
3 |
45 |
1.0 |
The high strength cement analytical test result of table 2 embodiment 1-4 preparation