JPS58141276A - Crushing agent for brittle material - Google Patents

Abstract

PURPOSE:To provide a crushing agent which retards hydration reaction, easy to use in crushing operation and suitable for commercial production, prepared by pulverizing calcia clinker obtained by burning limestone which contains iron oxide, silica and magnesia as fluxes. CONSTITUTION:Iron oxide and silica and/or magnesia are added to raw material limestone in 3-15wt% as Fe2O3, 0.5-5wt% as SiO2 and 1-7wt% as MgO, respectively, based on the CaO content of the limestone. The mixture is burned and resultant calcia clinker is pulverized to produce a crushing agent which swells by hydration and shows crushing action. Hydration retarder such as gypsum, sugar and sodium carbonate is added to the pulverized calcia clinker for adjustment of hydrating property.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crushing agent for brittle objects such as rocks and concrete that utilizes the hydration expansion pressure of carunac linker.

Recently, there has been a rapid increase in the number of crushing and demolition works for concrete structures. However, they are gradually becoming more common around cities, and the noise, vibrations, dust, etc. generated during these operations are causing a lot of pollution.

As a countermeasure against this pollution, a method has been announced in which the object to be crushed is filled with various expandable substances and crushed by the pressure of the collapsing material.
The quicklime crushing method is known as an alternative method.

The principle of this construction method is as follows.

Quicklime (C@b) reacts with water (HsO) to form slaked lime [C
a(OR>m) It is sharp and generates heat during reaction. This CaO
→The pressure of the volume ** during the reaction of Ca(OR)m is the one used for crushing brittle objects. However, it is difficult to apply the above reaction to mourning, which is a very fast reaction, and to planned demolition work of KIllB structures. In order to delay the water utilization reaction rate of quicklime, a lance-sized amount of a chemical (retardant) is also mixed with the quicklime. However,
At present, the reaction rate of C10 cannot be sufficiently controlled by these retarders.

The present invention eliminates the drawbacks of conventional quicklime-based II refining agents and makes it possible to sufficiently retard the water utilization reaction rate,
It is intended to provide a crushing agent pipe that is easy to use during construction and is a brittle material for industrial green molds.

The brittle crushing agent of the present invention is obtained by finely pulverizing calcined clinker in which C10 crystals have grown, which is obtained by firing a mixture of limestone and iron oxide and 3II* and/or magnesia at 7 lux. It is used alone or in combination with a water usage rate retarder. The details will be explained below based on the examples. A small amount of additives are added to limestone and fired at a high temperature to form quicklime particles. It has been found that there are two methods: to promote setting, or to prevent the lime from coming into direct contact with water or steam by placing a thin, digestible layer on the surface of the quicklime particles.

However, in the present invention, in order to increase the digestibility of the quicklime-based swelling agent, we take the former method as a hint and create a calcareous raw material (by adding a small amount of additives and calcining at a low northern temperature). research on growing quicklime particles.

When calcining limestone at a high temperature, in the range of 900 to 1200°C, the crystal particles of CaO are 1i chlorine Iik, but 1
When the temperature exceeds 300°C, the particles suddenly grow to 6 microns (9), and the hydration reactivity gradually decreases as the size of the particles increases. C
The growth of aO crystal particles, in the case of quicklime-based crushing agents, prevents digestion before use and reduces the active ingredient (and therefore crushing efficiency) during use.
This will increase the crushing time and extend the crushing time.

When manufacturing quicklime-based crushing agents on an industrial scale, the present invention aims to apply a small amount of uniform flux to raw limestone in order to grow CaO crystals by calcining limestone at relatively low temperatures and in a short time. I thought about adding it. First, it should be recognized that the addition of iron oxide is inexpensive, easy to use industrially, and very effective. Calcium ferrite (C) is produced by adding iron oxide to limestone and firing it.
10・1'＠lo＠ l 2CaO・F＠10m) promotes the growth of quicklime crystal particles, and as a result, quicklime becomes stable for a long time in air, and water utilization occurs after several hours in water. It became clear that Calcium ferrite is so water i! According to the test report regarding the hydration property, it is known that the hydration property is relatively large, and therefore the Ca
In addition to the effect of promoting O crystal growth, it also increases the crushing effect as an l1w& agent. As raw materials for iron oxide,
Irscale, magnetite, hematite, laterite, highlight cinder, etc. are used.

According to the present invention, when iron oxide and silicic acid coexist, iron silicate I! Hanawa 2FeO-8iOm (faya
lile) is *rs, shi, this significantly promotes the growth of quicklime crystal grains, and together with iron oxide as a camp flux i! A friend discovered that adding acid is effective. This 2
The melting point of FeO-8i01 is 1165°C, but FeO
When 2FeO.5t (h) coexists, the crystal point is 11
The temperature is even lower (25°C), which allows C10 crystal particles to grow uniformly.

In addition to the above, in order to promote the growth of CaO crystal particles and improve the digestion resistance, gehl@nit and ak were added.
mel 111 to which is a solid solution of ermanite
(2CaO・Al40B'S 1o2-2CaO-
MgQ *310x series) is also effective, and ironm
ontkcel 1 ite(CaO-Fe04i0m
) 4 It was found to be effective.

In addition, as for the 7 lacs for industrial scale production of crushing agents, consideration has been given to the fact that the calcination is carried out at a low temperature for several hours, and that the calcination can be carried out in a rotary furnace from the viewpoint of productivity.

Based on the above-mentioned research, we have found that a flux, i.e., an iron oxide raw material (main components: FeO, Fe3O
3+ Impurity: Blu em J! 10m + T t
(ow, etc.) and silicon 11J [material (main component: 5ins, impurity: umOs +W@A (h, etc.) and/or magnesia raw material (droitite, nickel slag, serpentine, etc.) I
The crushed steel of the present invention, which is obtained by adding limestone and calcining it at a temperature of about 1000 to 1500°C, is economical and highly effective.

Next, we will discuss the quantitative relationship of 7 lux added to KI [orthorhombite].

In the case of iron oxide, the amount added is 5 to 15 sulfur (by weight) based on the amount of CaO in the iron oxide raw material. If less than 5% of iron oxide is added, it is difficult to suppress the water utilization of quicklime, and the practicality becomes low. When iron oxide exceeds 3g6, quicklime crystal particles grow, C10 water supply gradually erodes, and plate-like crystals of Ca(OH)m are formed.

Therefore, the rise in temperature can be suppressed due to water conservancy. This effect of iron oxide is enhanced by the addition of a small amount of silicic acid or magnesia. The upper limit of suitable iron oxide addition is 15-,
Furthermore, if an excessive amount of oxidized iron pipe is added, in the operation of limestone firing in a rotary furnace, the 9% charge will be fused to the refractory material of the furnace wall, which will increase the firing temperature. In addition, crushed clinker has a large specific gravity, and when drilling into rock, concrete, etc., the moisture in the slurry and clinker powder separate, resulting in a crushing effect. It is dangerous because it lowers the

In quicklime paste crushing agents, the presence of small amounts of silicic acid is very effective for the growth of C10 crystals. The coexistence of iron oxide and a small amount of silicic acid strongly promotes the growth of CaO crystals, prevents digestion of the crushing agent during storage, and increases the activity (crushing effect) during use. The amount of sea bream added depends on the properties of the raw material limestone and the amount of iron oxide, but it is usually calculated as the amount of CaO in the raw limestone (151/I (weight)) as the 8i false amount in the silicic acid raw material.
The effect is clearly visible. However, when silicic acid in an amount exceeding 5% coexists with iron oxide, 5C10
- It is preferable because it generates a10 and 2CaO-8101 and reduces free -CaO.

The effect of magnesia added to Shishiro limestone is iron oxide,
Mums that inevitably come in from silicic acid and raw materials40
Due to the coexistence with M, a glassy melilite-based matrix grows at low temperatures, which supports the growth of P quicklime crystals and creates a crushing agent with high crushing ability. The amount of magnesia added is as MgO in the magnesia raw material.
The effect on the amount of CaO in the raw material limestone is recognized from 1 to 7 degrees, but the effect increases over 7 degrees.

As mentioned above, lA family limestone iron oxide and/or 1d
The calcia-tarin carcasses produced by calcining the addition of magnesia can be used as a crushing agent in a hydration chamber of 11K by simply pulverizing them. However, of course, ζO calcia clinker powder, gypsum, sugar-1 #ts to adjust the hydration property! It is also possible to use a well-known hydration rate retarder, such as soda, by adding it.

Next, the present invention will be explained in detail by way of examples.

1 311 Raw limestone and additives (I
Mill scale as iron phoenix I, silica as silica,
Calcia clinker tubes were made by calcining limestone and using dolomite as the material shown in Table 2. The firing temperature was 1500°C and the firing time was 1 hour.

The calcia clinker produced in 11lb was subjected to a digestion test using water vapor for 1 hour at 5 atmospheres in an autoclave, and the residual rate of C&0 was determined.

In addition, we measured the hydration temperature using a water calorimeter and investigated the rise in water temperature. In this case, the amount of water is 600cc.

Each hydrated sample used 1522 powder with a particle size of -88 microns, and the temperature rise after 10 minutes was compared. The test results are as shown in lI2.

From lI2, flux addition O1k% A41, 9 A2 with only a small amount of mill scale added, and A4 with a small amount of AS and zel scale and silica added outside the effective table range of the present invention.
In each of the samples, the CaO residue rate (II digestibility) did not reach 80SK, the water usage temperature increased by 40°C or more, and the water usage reaction rate was not sufficiently suppressed.

In contrast, Fe2 On + 810 according to the present invention
Samples Todoroki 5 to 9, in which n vMgO was blended, all had a Coo residual rate of 80 qIN or more and a hydration temperature increase of 40°C.
This shows that it has excellent digestion resistance and can maintain a high OII crushing effect during use.

2, 112 49 clinker, 3 tons of gypsum and 3-1 tons of bentonite were added to 60.29 IIt and crushed to a 88 micron residue of 10 to obtain a crushing agent.

This was injected as a slurry into a hole with a diameter of 25-1 and a diameter of 253 drilled in the center of a -15a*, 30sm high concrete specimen (C:8:A=1:2:4, W/c 5016). . The water content in the slurry was 50s with respect to the blended clinker.

As a result, the concrete specimen developed cracks in 5 hours and completely collapsed in 11 hours.

5) To the clinker of A65 shown in Table 2, gypsum (5s1 bentonite) 516 and sucrose [1,1 saccharide] were added and crushed in the same manner as in Example 2, and a concrete specimen was tested. Cracks appeared and the building collapsed in 13 hours.

4, l [17 clinker of I2, 2 s of gypsum, 3 pieces of bentonite, 0.116 s of rice bran, anhydrous II LIl powder α5
A pulverizer was added and pulverized to make a crushing agent.

In a limestone deposit, - a part K with a surface free area of about 50 m/hole, a hole of 1150 ml with a riplar drill, and a hole length s.
Holes were made in a staggered manner with a pitch of 60a+, and a polyethylene bag was placed in the holes in advance, and the crushing agent T slurry was filled into the bags. (III! is used because there are many natural cracks in limestone deposits.) As a result, a crack occurs in 6 hours, and in 24 hours, the crack II grows to 8-trench, and the volume increases by 1. Mining was possible.

1 person'□Patent attorney Tadashi Sato

Claims (1)

[Claims] For the raw material coal stone, 3 to 15 weight iron and cL 5 to 5 weight silicic acid and/or 1 to 7 of the CaO content thereof are added.
A brittle crushing agent made by finely pulverizing the mourning calcia clinker obtained by distributing the weight of magnesia and firing a mixture of kerosene.