CN100569694C

CN100569694C - Brushing gypsum

Info

Publication number: CN100569694C
Application number: CNB200710016838XA
Authority: CN
Inventors: 董志强; 董斌; 董杰
Original assignee: FEICHENG RUIDONG CONSTRUCTION MATERIAL Co Ltd
Current assignee: FEICHENG RUIDONG CONSTRUCTION MATERIAL Co Ltd
Priority date: 2007-07-13
Filing date: 2007-07-13
Publication date: 2009-12-16
Anticipated expiration: 2027-07-13
Also published as: CN101121587A

Abstract

The invention discloses a kind of brushing gypsum, it is that calcined gypsum powder, retardant, tackiness agent, water-holding agent, slaked lime and grain composition sand are carried out proportioning according to a certain percentage, load weighted calcined gypsum powder is dropped into mixing machine to be mixed, again retardant, tackiness agent, water-holding agent and slaked lime input mixing machine and calcined gypsum powder are carried out thorough mixing, the more husky input of grain composition mixing machine is mixed getting final product in ten minutes at last.Brushing gypsum of the present invention has unique excellent water-retentivity, cohesiveness and self expansion compensation function, avoid the generation of the dry and cracked phenomenon of hollowing, and cost is low, can promote the use of on a large scale.

Description

Brushing gypsum

Technical field

The present invention relates to material of construction, especially brushing gypsum.

Background technology

Along with the fast development of novel energy-conserving materials for wall, released new wall material product system based on coal gangue, flyash and air-entrained concrete building block, flyash brick, gypsum block, Yellow river silt brick, all kinds of Light trabs, combined wall board.The large-scale popularization of these new wall materials is used, all run into the unconformable with it problem of cement sand plaster material, new wall material such as autoclaved fly ash brick, air-entrained concrete building block particularly, because water-absorbent is strong, the distortion shrinking percentage is big, both made treatment processs such as adopting interfacial agents, plug-in woven wire, the hollowing cracking phenomena also takes place often, becomes the insoluble common quality defect of current construction industry, and the large-scale popularization that directly has influence on these novel wall materials is used.

For adapting to the development of new wall material, brushing gypsum has appearred, and the technology relevant with the application is:

1, the Chinese patent publication number is the manufacture method that CN1369457 (application number 02111055.7) discloses a kind of brushing gypsum, it is to add retardant and water-holding agent in the citric acid gypsum that processed is crossed, wherein the add-on of retardant and water-holding agent is the 1-4% of citric acid gypsum, the amount ratio of retardant and water-holding agent is 1: (1-2), again moistening terra alba is sintered into the mixed gypsum of semi-hydrated gypsum or semi-hydrated gypsum-dehydrated gyp-, regrind into fine powder, firing temperature is at 100-180 ℃.

Its weak point is: it is the calcining of carrying out terra alba after adding additive again, and some additive is understood ineffectively in calcination process, can very big influence be arranged to the quality of the brushing gypsum produced, causes quality product very unstable.

2, the Chinese patent publication number is that CN1528702 (application number 03125477.2) discloses a kind of brushing gypsum and preparation method thereof, it comprises semi-hydrated gypsum, water-holding agent, it is characterized in that: also add anhydrous anhydrite powder, exciting agent, the per-cent of the shared gross weight of each component is: anhydrite powder 80-90, semi-hydrated gypsum 3-13, exciting agent 1-7, water-holding agent 0.1-0.3.Its preparation method, 1), natural anhydrite is utilized industrial ball mill grinding, fineness is controlled at 200 mesh sieve surpluses less than 3%, and specific surface area is at 4500 ~ 7000cm ²/ g; 2), raw material is prepared: per-cent by weight, anhydrite powder 80-90, semi-hydrated gypsum 3-13, exciting agent 1-7, water-holding agent 0.1-0.3; Also can add hydraulicity cement as required, the per-cent that hydraulicity cement accounts for gross weight is 0-15; 3), above-mentioned each raw material is measured respectively, thorough mixing in mixer, brushing gypsum surface layer powder.

Because its main component is natural anhydrite, but real natural anhydrite is seldom, that is to say starting material very little, causes the brushing gypsum cost produced very high, is not suitable for promoting on a large scale.

In addition, the common defects of above-mentioned two documents is that bonding strength is not very high, and the hardness on surface is also very low.

Summary of the invention

The application's purpose is the deficiency that overcomes above-mentioned brushing gypsum quality instability, cost height, caking ability difference, provides a kind of novel environment friendly plastering mortar, i.e. brushing gypsum.

For achieving the above object, the application's brushing gypsum is made by following method:

1, earlier plaster of paris stone (dihydrate gypsum) is carried out fragmentation, homogenizing, grinding is selected 120 purpose gypsum powders by powder separating machine then;

2,120 purpose gypsum powders are put into fluidizing furnace calcining 1 hour, calcining temperature is controlled at 150～180 ℃, becomes the calcined gypsum powder;

3, the calcined gypsum powder is carried out ageing 7-14 days;

4, do the various raw materials of weighing accurate in scale (all referring to weight part) of husky 10-30 part according to 10 parts in calcined gypsum powder, retardant 0.01-0.05 part, tackiness agent 0.01-0.02 part, water-holding agent 0.01-0.2 part, slaked lime 0.5-1 part and grain composition, described grain composition sand is to be formed by 40-70 order and the common dried sand of the 70-140 purpose mixed by 1: 1;

5, load weighted calcined gypsum powder is dropped into mixing machine and mix, again retardant, tackiness agent, water-holding agent and slaked lime input mixing machine and calcined gypsum powder are carried out thorough mixing, the more husky input of grain composition mixing machine is mixed getting final product in ten minutes at last.

Can suitably add a little hydraulic cementing materials in order to improve alkaline environment, generally account for 5～15% (weight percents) of calcined gypsum powder.

Described retardant mainly contains citric acid, Trisodium Citrate, tartrate, HG type and S type retardant etc.;

Described tackiness agent has pasted starch, normal-temperature water soluble polyvinyl alcohol powder, redispersable latex powder etc.;

Described water-holding agent mainly is exactly methylcellulose gum (MC).

The every performance index of the present invention see Table 1, and the detection operative norm is Q/JCJRD019-2004 " a RD-brushing gypsum ".

The invention has the beneficial effects as follows:

1, because the calcined gypsum powder used of the present invention is a low temperature burns slowly and be aged terra alba in the warehouse, quality is more stable; The methylcellulose gum and the tackiness agent that add make the present invention have unique excellent water-retentivity, cohesiveness and self expansion compensation function, avoid the generation of the dry and cracked phenomenon of hollowing.

2, main raw material(s) of the present invention is a plaster of paris stone, the raw material abundance, and price is lower, and the brushing gypsum cost of producing is reduced greatly, can promote the use of on a large scale.

3, do alkali-activator owing to added slaked lime, effectively improved the alkaline environment (pH is greater than 10) of product, avoided in use to corrosion of metal.

Embodiment

Be that example further specifies enforcement of the present invention with 1000Kg (1 ton) calcined gypsum powder below.

1, earlier plaster stone is carried out fragmentation, homogenizing, grinding then is by the capable 120 purpose gypsum powders of selecting of powder separating machine;

2,120 purpose terra albas are put into fluidizing furnace and calcined 1 hour, calcining temperature is controlled at 160 ℃, becomes the calcined gypsum powder;

3, the calcined gypsum powder was carried out ageing 9 days;

4, the accurately water-holding agent of the tackiness agent of the retardant of the calcined gypsum powder of weighing 1000Kg, 2.1Kg, 1.5Kg, 2Kg, 50 kg slaked lime and the grain composition sand of 1500Kg, earlier terra alba being dropped into mixing machine stirs, again retardant, tackiness agent and water-holding agent input mixing machine and terra alba are carried out thorough mixing, the more husky input of grain composition mixing machine is mixed getting final product in ten minutes at last.

Described retardant is following at least a citric acid, Trisodium Citrate, tartrate, HG type or S type retardant;

Described tackiness agent is one of following: pasted starch, normal-temperature water soluble polyvinyl alcohol powder, redispersable latex powder;

Described water-holding agent is methylcellulose gum (MC).

Table 1 (the every performance index of the present invention)

Project	Unit	Technical indicator
Project	Unit	Technical indicator	Operable time	min	≥60
Presetting period	min	≥75	Operable time	min	≥60
Presetting period	min	≥75	Final setting time	min	≤240
Water retention	％	≥75	Final setting time	min	≤240
Water retention	％	≥75	Splitting resistance	Mpa	The 24h flawless
Folding strength	Mpa	≥2.0	Splitting resistance	Mpa	The 24h flawless
Folding strength	Mpa	≥2.0	Ultimate compression strength	Mpa	≥4.0
Shear bonding strength	Mpa	≥0.3	Ultimate compression strength	Mpa	≥4.0
Shear bonding strength	Mpa	≥0.3	Shrinking percentage	％	≤0.06

Claims

1, a kind of brushing gypsum is characterized in that, it is made by following method:

(1) earlier plaster of paris stone is carried out fragmentation, homogenizing, grinding is selected 120 purpose gypsum powders by powder separating machine then;

(2) 120 purpose gypsum powders are put into fluidizing furnace calcining 1 hour, calcining temperature is controlled at 150～180 ℃, becomes the calcined gypsum powder;

(3) the calcined gypsum powder is carried out ageing 7-14 days;

(4) according to the various raw materials of weighing accurate in scale of 10 parts in calcined gypsum powder, retardant 0.01-0.05 part, tackiness agent 0.01-0.02 part, water-holding agent 0.01-0.2 part, slaked lime 0.5-1 part and the husky 10-30 part of grain composition;

Described grain composition sand is to be formed by 40-70 order and the common dried sand of the 70-140 purpose mixed by 1: 1;

(5) load weighted calcined gypsum powder is dropped into mixing machine and mix, again retardant, tackiness agent, water-holding agent and slaked lime input mixing machine and calcined gypsum powder are carried out thorough mixing, the more husky input of grain composition mixing machine is mixed getting final product in ten minutes at last; Above-mentioned umber all refers to parts by weight;

Described retardant is citric acid, Trisodium Citrate or tartrate;

Described tackiness agent is pasted starch, normal-temperature water soluble polyvinyl alcohol powder or redispersable latex powder;

Described water-holding agent is a methylcellulose gum.

2, brushing gypsum as claimed in claim 1 is characterized in that, also can add the hydraulic cementing materials that accounts for calcined gypsum powder 5～15% (weight percent) when making.

3, brushing gypsum as claimed in claim 1 is characterized in that, described raw material preferred weight part is:

Husky 15 parts of 10 parts in calcined gypsum powder, 0.021 part of retardant, 0.015 part of tackiness agent, 0.02 part of water-holding agent, 0.5 part of slaked lime and grain composition.