JPS5899147A - Hydraulic cement composition comprising blast furnace water-granulated slag and gypsum dihydrate principally - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention The present invention provides a fine powder raw material of granulated blast furnace slag and trihydrate gypsum.
The present invention relates to a hydraulic cement composition obtained by adding and mixing a powder hardening accelerator to a mixture.

The granulated furnace slag, which is one of the raw materials for the hydraulic cement composition of the present invention, is slag as a by-product of blast furnaces for iron-making. This is the so-called removed gypsum obtained in the smoke desulfurization process.

In general, excavation work in civil engineering works involves assimilation of waste water, and safe treatment of hazardous waste discharged from mines and smelting plants involves solidifying it and making it harmless.
Conventionally, water-hardened quicklime, such as boltland cement or blast furnace cement, has been used for its preparation.

However, all of these materials are fired at high temperatures, and their production requires high-energy metal. For example, Portland cement requires 800.000 KcaV clinker t for firing.
One disadvantage is that it requires the use of high energy consumption materials, such as the power consumption of 120 KW, H, and tonf.

As is well known, Portland cement and blast furnace cement have a tendency to be too sensitive to hydration, making their use rather inconvenient. In addition, Portland cement has poor acupuncture resistance, and concrete structures using it have drawbacks such as expansion cracks, and corrosion due to gold-containing substances such as humic acid inhibits the development of strength.

The purpose of the present invention is to eliminate all of these drawbacks and to provide an inexpensive desilted soil, assimilation of soft ground, and a coagulant by using waste materials that are not affected by granulated blast furnace slag. This is achieved by the hydraulic cement composition of the present invention, which is formed by adding and mixing a powder mixture of aluminum sulfate calcium hydroxide and an alkali sulfate salt as a total hardening accelerator to a fine powder raw material mixture with water gypsum.

To explain the composition of the present invention, its main raw materials, granulated blast furnace slag and gypsum trihydrate, are by-products of iron-making blast furnaces and waste products from sulfur dioxide gas, and the former itself contains very little. Although it has no reactivity with water, it seems to have a kind of latent reactivity, especially in combination with the latter.
It has recently been discovered that the hardening accelerators aluminum sulfate, calcium hydroxide, and potassium sulfate have the effect of significantly accelerating hardening in water utilization reactions by adding and mixing a mixture of alkali sulfate salts such as sodium sulfate as a powder. It is what was done.

The cause and mechanism of this promotion of hydraulic hardness are not fully understood at present, but ettrin guide (E
ttringite ) (3CaO-A&03・3C
aSO4・31-33H20) is estimated. That is, in this reaction, the granulated slag with latent hydraulic properties elutes CaO and A&03 from its surface by the action of the hardening accelerator consisting of aluminum sulfate, calcium hydroxide, and caustic sulfate, and then dissolves trihydric slag. Gypsum (CaSO4
・2H20) to form a nitride/guide, and after about 7 days, the short-term strength was fully discovered, and furthermore, CaO in the slag
' It is thought that a hydrate of SiO2.nH2O is formed and long-term strength is developed after 28 days.

Next, the following results are obtained from the results of experiments on preferred blending of each component of the hydraulic cement composition of the present invention. The mixing ratio of granulated blast furnace slag, which has been crushed into a fine powder, and trihydrate gypsum is preferably in a weight ratio of granulated blast furnace slag: trihydrate gypsum = 95 to 65:5 to 35, assuming a total of 100 parts by weight. ,
The addition ratio of the curing accelerator is preferably in the range of 1 to 6 times.

The ratio of each component in the curing accelerator is preferably within the following weight ratio: aluminum sulfate: calcium hydroxide: alkali sulfate (calculated as potassium sulfate) = 25-40:55-30:20-30. .

Next, Example tap water.

Finely powdered granulated slag, 75 parts by weight, powdered industrial gypsum, 25 parts by weight
Parts by weight are each taken and mixed thoroughly. To this raw material, 1.49 parts by weight of aluminum sulfate, 1.5 parts by weight of potassium sulfate, 1.5 parts by weight of calcium hydroxide, and 1.5 parts by weight of powdered wood hardening accelerator gold were added, and the mixture was ground and mixed to form a hydraulic composition. to make. The weight of the hydraulic composition of the present invention per 100 parts of water
Cement mortar was made by adding r: 50%, 80%, 100%, and 150%, respectively, for 7 days and 2 days.
The results of calculating the compressive strength (volume/rrn) after 8 days of aging are shown in the following table.

Table-1 =Taki, ::Uni:;. 2. ::2,'2; In view of the experimental results, it was found that the granulated blast furnace slag and industrial gypsum of the present invention were used as all raw materials, and the powdered water containing a powder mixture of sulfurized aluminum, calcium hydroxide, and alkali sulfate as a hardening accelerator was used. It has been confirmed that the hard cement composition has a substantial hardening effect for solidifying waste water, making hazardous waste safe, and stabilizing soft ground and sludge ground.

According to the present invention, it is possible to obtain a cement composition that completely utilizes waste materials, consumes no energy, and has mild and reliable hydraulic properties. .

Patent applicant: Mitsui Construction Co., Ltd.

Claims (1)

[Claims] l) A powder mixture of sulfurized aluminum, calcium hydroxide, and an alkali sulfate salt is added and mixed as a hardening accelerator to a finely powdered raw material mixture of granulated blast furnace slag and gypsum trihydrate. Hydraulic cement composition. 2) The mixing ratio of the blast furnace granulated slab and trihydrate gypsum is tj
Granulated blast furnace slag by T: dihydrate ← 5-65: 5-35
The composition according to claim 1), wherein the ratio is within the range of . 3) The composition of the curing accelerator is within the range of aluminum sulfate:calcium hydrate:alkaline sulfate (calculated as potassium sulfate)=25-40:55-30:20-30 by weight. The composition according to scope 1). 4) The composition according to claim 1, wherein the ratio of the fine powder raw material mixture to the hardening accelerator j is 100 to 1 to 6 by weight.