CN1105344A

CN1105344A - Method for making non-clinker cement by wet-milling flyash and product thereof

Info

Publication number: CN1105344A
Application number: CN94111221A
Authority: CN
Inventors: 高杰生; 杜庆林
Original assignee: LIANYUNGANG CITY INST OF BUILDING ENGINEERING
Current assignee: LIANYUNGANG CITY INST OF BUILDING ENGINEERING
Priority date: 1994-01-13
Filing date: 1994-01-13
Publication date: 1995-07-19

Abstract

The non-clinker cement is made up from wet flyash discharged from steam-power plant, lime and gypsum through separately grinding and mixing. This low-grade (No.275) cement may be used to produce non-burning brick or building block, mortar and concrete No.13, or to mix with ordinary Port/and cement.

Description

Method for making non-clinker cement by wet-milling flyash and product thereof

The present invention relates to a kind of production method of pulverized fuel ash cement and the manufacturing of goods thereof.

Flyash is a kind of artificial pozzolanic materials, is the waste residue that discharge in the fuel-burning power plant, and per ten thousand kilowatts of generated energy have 7500 tons of flyash to discharge approximately.Mainly be to stack or enter rivers,lakes and seas at present, because lime-ash occupies a large amount of farmlands or contaminate environment, stop up the river course, therefore how developing flyash is an important subject.Burned brick after fly ash float system high refractory brick, system cement being arranged, produce silicate lock, production gas concrete or mix clay of success, and directly be used for roadbed bed course etc., but total utilization of these purposes is less than 20% of its total flow rate.

Because the wet ash discharge amount of power plant is big, utilize difficulty, become dry ash if handle wet ash, then the cost of goods improves, then all effected on economic benefit and social benefit.

The objective of the invention is to provide a kind of with wet fly-ash directly levigate after, be equipped with auxiliary material and produce cement of low index, and be processed into the method for various cement products or the direct fabricated product of use fine-ground fly-ash with this cement.

Implementation content of the present invention is described below:

To a kind of method for making non-clinker cement by wet-milling flyash of using, adopt the wet ash discharge of power plant to make raw material exactly, and be equipped with a kind of cement of low index that auxiliary material is produced, and the independent method of using of wet-milling flyash.

Flyash has certain activity, it is to be the silica-aluminum materials of main component with silicon oxide and aluminum oxide, itself adds behind the water non-sclerous, but the calcium hydroxide that produces during with lime, gypsum aquation can carry out the secondary hydration reaction, generates the compound with hydraulic gelling matter.Therefore it is possible utilizing these characteristics to produce cement of low index.

The composition of various raw materials of preparation cement of low index sees Table 1, table 2, table 3.

The chemical ingredients of table 1 flyash (%)

Numbering loss on ignition SO ₂Al ₂O ₃Fe ₂O ₃CaO MgO SO ₃

77 0 50.7 34.95 3.45 7.78 0.38 0.73

83/1 11.28 51.32 29.67 4.60 2.57 1.03 -

83/2 11.70 47.20 28.20 2.50 4.30 0.65 0.55

85/1 11.92 55.40 33.49 3.67 3.92 2.80 0.43

85/2 12.27 48.92 25.23 3.80 3.20 0.81 -

Table 2 lime chemical ingredients (%)

Number total CaO effective CaO MgO

1 71.23 65.60 6.33

2 89.28 83.67 -

Table 3 salt gypsum chemical ingredients (%)

Numbering CaO MgO SlO ₂Al ₂O ₃SO ₃

79 28.71 1.29 7.23 3.55 40.77

85 17.47 0.43 8.28 0.97 41.28

The technology of producing the wet fly-ash clinker-free cement is:

With levigate in power plant's wet-discharged coal ash input ball mill, levigated ash material is by 4900 holes/square centimeter sieve, when its screenings gets final product discharging less than 5%.Qualified levigate wet ash material is directly entered storage tanks, dewater naturally, when water content can be imported levigate grey stockyard stored for future use less than 70% the time by it.With unslaked lime, salt gypsum and calcium lignin sulphonate were dry grinded the thin surplus of extremely passing through 4900/ hole square centimeter sieve respectively less than 5% o'clock, can in accordance with regulations cooperation ratio and wet-milling flyash be mixed into clinker-free cement in addition.

By test mixture fixed optimum proportion was mixed with 275 ^#Wet-milling flyash clinker-free cement can both meet national standard.The proportioning of its each component is as follows:

Levigate wet fly-ash 55-75%

Fine grinding quicklime 20-35%

Levigate plaster stone 4-5%

Calcium lignin sulphonate 0.2-0.3%

By above proportioning, a kind of production wet fly-ash does not have grog low grade (275 ^#) performance of cement lists in table 4, table 5, table 6, table 7 with relevant test data:

Table 4 275 ^#The strength detection of clinker-free cement

Number levigate coal ash exciting agent water folding strength (MPa)

Consumption (%) consumption (%) consumption (%) 3 days 7 days 28 days 60 days 90 days

Standard-2.5 5.0--

13 67.6 32.4 50.0 14 2.5 6.0 6.5 6.3

14 67.6 32.4 50.0 24 4.0 7.4 8.2 7.9

Ultimate compression strength (MPa)

3 days 7 days 28 days 60 days 90 days

- 13.0 27.5 - -

6.8 14.9 33.0 46.1 52.4

12.6 20.3 39.2 51.4 56.0

The wet-milling ash concrete can meet the intensity of national standard from 28 days as seen from Table 4, can surpass the intensity that GB is stipulated to 60-90 days its intensity.

Table 5 275 ^#The performance test of wet-milling flyash clinker-free cement

Project standard GB 1344-92 275 ^#Test result

Fineness (%)≤10.0 8.0

SO ₃(%) ≤3.5 2.8

Time of coagulation (time: divide)

Initial set must not be early than 0:45 3:00

Final set must not be early than 10:00 8:35

Volume stability

(boiling process) is qualified

Folding strength

(MPa)

7 days 2.5 3.7

28 days 5.0 6.0

60 days-6.5

90 days-7.0

Ultimate compression strength

7 days 13.0 18.6

28 days 27.5 35.6

60 days-48.4

90 days-55.0

By table 5 visible 275 ^#Clinker-free cement meets national standard fully.

Utilize wet-milling flyash clinker-free cement can allocate auxiliary material (as original state flyash, milk of lime, sand) into, make non-burning brick, concrete segment after the natural curing through rolling.Also wet-milling flyash directly can be mixed in the silicate cement, can save the silicate cement of 15-25%; When wet-milling flyash further dewaters, when water content 30% when following, can be separately as commodity selling, behind the adapted exciting agent, for building a wall, whitewash use.

Table 6 275 ^#Clinker-free cement is made C13 ^#Concrete performance

Numbering material mixture ratio (Kg/M ³) water cement ratio slump ultimate compression strength

Levigate grey exciting agent medium sand rubble (CM) (MPa)

3 days 7 days 28 days 60 days 78 days

5 237 113 592 1173 0.7 1.0 - - 20.3 - 28.4

7 245 119 565 1112 0.6 0.5 2.9 5.9 24.2 - -

Table 7 is with 275 ^#The data with mortar are built in the cement preparation by laying bricks or stones

Numbering material mixture ratio (Kg/M ³) water consumption denseness ultimate compression strength (MPa)

Levigate grey exciting agent medium sand (%) (CM) 3 days 7 days 28 days 60 days 90 days

1 544 261 1610 57 3.0 - 17.4 29.6 - -

2 363 174 1611 69 3.0 - 10.7 19.6 - -

3 218 104 1610 81 3.0 - 6.2 15.0 - -

5 181 87 1608 6.9 - 2.8 6.6 - -

7 107 52 1606 2.0 0.4 0.6 3.7 4.9 6.0

To do detailed elaboration to enforcement of the present invention by embodiment below.

Accompanying drawing 1 is the process flow sheet of production wet-milling flyash clinker-free cement.

Embodiment 1:

With reference to accompanying drawing 1, the wet fly-ash that the fuel-burning power plant is discharged, with grinding in the slurry pump input ball mill, when the slip of in ball mill, discharging by 4900 holes/CM ²Sieve, its screen over-size got final product discharging less than 5% o'clock.The slurry that is gone out is transported in the nature dehydration pond with rotary conveyor and is gone out excessive moisture by its natural drop, and the water that drop goes out makes it enter circulatory pool, uses during for the water content of adjustment mortar.Be lower than 70% when mortar dewaters in the pond to the water content of mortar in dehydration naturally, be higher than at 30% o'clock and be available rotary conveyor and transport to the mortar stockyard and deposit stand-by.

With 0.676 ton of fine-ground fly-ash (water content≤20%), 0.27 ton of unslaked lime, 0.048 ton of plaster stone, 0.02 ton of calcium lignin sulphonate places amalgamator to stir, to mixed evenly after, can obtain being equivalent to 1 ton 275 ^#The flyash clinker-free cement.

Embodiment 2:

With embodiment 1 made 275 ^#Clinker-free cement mixes appropriate amount of auxiliary materials (as original state flyash, milk of lime, sand), after fully mixing, makes adobe in the input brick press, promptly becomes non-burning brick again after natural curing.Per ton 275 ^#But 600 of cement making burn-free bricks.

Embodiment 3:

With embodiment 1 made 275 ^#Cement mixes an amount of auxilliary mashed (as original state flyash, milk of lime, sand), is pressed into the building block base in the input building block making machine after mixing, and after natural curing, promptly becomes non-burning brick then.

Per ton 275 ^#Clinker-free cement can be made 80 of baking-free building blocks.

Embodiment 4:

With embodiment 1 prepared water content reach 70% fine-ground fly-ash further dewater to water content be 30% o'clock, sell in the double-layer plastic bag of can packing into.

Embodiment 5:

The fine-ground fly-ash that will make by embodiment 1 is added in the silicate cement in the ratio of 15-25%, can save the silicate cement of 15-25%.

Can reduce hydration heat if be used for mass concrete.

Embodiment 6:

With the fine-ground fly-ash of embodiment 1 gained, further dewater to water content less than 30% o'clock, can sneak into exciting agent, for building a wall, using when whitewashing.

Claims

1, a kind of wet-milling flyash clinker-free cement (275 ^#Cement), the base-material that it is characterized in that this cement is thermal power plant's wet-discharged coal ash, can pass through 4900 holes/CM through grinding ²Behind the sieve, and make its moisture≤70%, promptly by following proportioning preparation:

Fine-ground fly-ash (water content≤70%) 55-75%

Fine grinding quicklime 20-35%

Levigate plaster stone 4-5%

Calcium lignin sulphonate 0.2-0.3%

To be mixed material behind thorough mixing, 275 ^#Cement.

2, according to the cement of claim 1, it is characterized in that this cement can be used as cement of low index and uses, making C ₁₃Concrete can be used following proportioning:

275 ^#1 part of cement;

Medium sand 1.5-2 part;

Rubble 3.5-4 part;

Water 0.6-0.7 part;

After crutcher stirs.

3, according to the cement of claim 1, it is characterized in that 275 ^#Cement is used to make the proportioning of laying bricks with mortar:

275 ^#1 part of cement;

Medium sand 1.2-2.0 part;

0.5 part in water;

After fully stirring evenly, promptly use.

4,, it is characterized in that being equipped with an amount of original state flyash, milk of lime, sand with this cement can make non-burning brick, baking-free building block according to the cement of claim 1.

5, according to the fine-ground fly-ash described in the claim 1, it is characterized in that can directly mixing in the silicate cement, and do not influence its quality with this fine-ground fly-ash, its blended ratio is:

Silicate cement 75-85%

Fine-ground fly-ash 15-25%.