JPS5823350B2 - Lining material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a lining material for lining a container containing molten iron or steel, which has calcined granular dolomite as a base material and contains organic and inorganic additives. Regarding.

A number of materials are already known for lining containers containing molten iron or steel, particularly ladles. These materials can be processed horizontally or from centrifugal tamping machines without the use of molds. The materials can be applied to the container walls by vertically projecting them with so-called slingers after the mold.

Such materials can be basic or acidic, as shown for example in German Patent Applications Nos. 5,240,4026 and 1,229,438.

These documents describe the incorporation of organic additives in the form of mineral oil or mineral oil and fatty acids into such materials in order to improve their properties.

The L.L material described in German Patent Application No. 12 29 438 is made of dolomite to which 0.1 to 0.2 parts by weight of neutral mineral oil have been added to reduce dust emissions.

Materials based on calcined dolomite have the disadvantage of a short shelf life due to the very strong tendency of calcined dolomite to hydrate.

In this regard, the Patent Application Publication No. 14 of the Federal Republic of Germany
Column 2, lines 10 to 12 of the specification of No. 71192 states that the hydration effect due to the natural moisture of the atmosphere cannot be effectively prevented by employing a hydrophobic agent such as a hydrocarbon oil. It has been stated.

Therefore, present knowledge. Calcined dolomite-based materials containing organic additives cannot be stored for extended periods of time.

Apart from extending the shelf life of the material through the inclusion of mineral oils and fatty acids, dolomite-based basic materials can also be used, like magnesia-based materials, with the addition of pitch or tar. As shown in the publications mentioned above.

Pitch or tar is unpleasant due to the smoke and odor of burning when using such materials.

The addition of inorganic binders is not proposed.

The object of the present invention is to provide a lining material based on calcined dolomite that can be stored for long periods of time, more than 3 months, without hydration, in other words, does not tend to change its properties by absorbing moisture from the atmosphere. It's about making suggestions.

For this reason, the lining material according to the invention contains from 1 to 6 parts by weight of natural triglyceride oil or a mixture of triglyceride oils, based on the dry weight of the entire lining material;
Or only 6 weight section drying.

silicates or phosphates or mixtures of these salts.

According to the present invention, since the triglyceride oil coats the calcined dolomite particles, which have a strong tendency to hydrate, in a film, it prevents the dolomite particles from absorbing moisture from the atmosphere and allows the lining material to last for a long time without absorbing moisture. Can be stored for a period of time.

In addition, triglyceride oil is used in a proportion of only 1 to 6% by weight, and also serves as a lining agent at room temperature, coagulating the lining material to a certain strength at room temperature, and by tamping or using a slinger. The lining material, which is applied to the container by projection, adheres to the container wall.

On the other hand, sodium or potassium silicates or phosphates, when used in proportions of 2 to 6 parts by weight, react with the calcined dolomite during heating of the applied lining material and bind the dolomite particles.

In a preferred embodiment, the proportion of triglyceride oil is between 2 and 4 parts by weight.

It is advantageous to use vegetable triglyceride oil, especially soybean oil, and if you add 0.5 to 3 parts by weight of dry paper powder (finely ground paper), it will accelerate drying after application. This makes it more suitable for applying lining materials.

The addition of paper powder is preferably 1 to 2 parts by weight.

For example, it is also possible to add carbon black, graphite or ground coke as 1 to 3 parts by weight carbon material.

The lining material proposed according to the invention can be applied by compaction or by projection using a slinger.

For example, when lining a ladle, the blended lining material is projected with great force and high velocity by the impeller head of the slinger into the space between the ladle wall and the inserted special mold.

Once the lining is complete, the mold is removed.

Because the triglyceride oil provides a high internal cohesive force in the lining material, the lining not only maintains its shape but also has sufficient wet strength to withstand handling when the ladle is transported to the kiln.

The value measured with a conventional Fisher measuring device for measuring the depth of depression is 90 or more.

The lining is then heated or even filled into a ladle where molten iron or phosphate reacts with the dolomite and binds the dolomite particles.

The calcined dolomite used for the proposed lining material is
Obtained from natural dolomite sources, conventionally calcined following crushing and/or grinding and optionally sieving for removal and recombination of special grain size components or for removal of special grain size components. receive.

The term dolomite here refers to the chemical formula CaCO32MgC
Contains not only substances with O3, but also CaCO3 and M
It also includes materials in which the proportion of gCO3 varies greatly and materials in which magnesium in dolomite is replaced by iron or manganese.

For example, 54.5% CaCO3 and 42.8% MgC
Dolomite containing O3 and 3.9% CaCO3 and 89.
22%.

Dolomite, which contains MgCO3, is a well-known natural material.

Particle size analysis of the calcined dolomite used to produce the proposed lining material shows that at least 3.
The remaining 65% has a particle size distribution ranging from 0.09 mm to 4 mm or 6 mm.

If desired, the upper limit of the particle size distribution can be 2 mm or 3 mm.

The proportion having a particle size of 0.09Tt7IL or less can be 50%.

(j) Ground dry silicic acid as binder used in the lining material according to the invention) IJum or potassium silicate, sodium metaphosphate or potassium metaphosphate or mixtures thereof are used in proportions of 2 to 6 parts by weight.

The proposed lining material (1) is manufactured by methods commonly used for mixing dry ingredients.

For example, calcined dolomite and ground dry binder are first mixed and then the appropriate amount of natural triglyceride oil is added.

Alternatively, the calcined dolomite may be mixed with triglyceride oil and this mixture then combined with a ground dry binder so that the triglyceride oil coats the calcined dolomite particles and reduces the tendency of the calcined dolomite to hydrate. It is possible.

However, according to the present invention, triglyceride oil is used,
The oil may be mixed prior to addition of the paper flour bed to prevent the triglyceride oil from being absorbed by the porous paper flour bed.

Triglyceride oils can be prepared by first heating the triglyceride oil to a temperature of, for example, 60°C to reduce its viscosity, and then injecting these particles through a nozzle while stirring the solid particles in a mixer, thereby reducing the mixing time excessively. It is advantageously used by ensuring as uniform a distribution as possible without lengthening.

4. The paper powder bed or finely crushed paper that can be added to the proposed composition is powdered paper pieces that have been cut to a maximum fiber length of 3 mm to 3 mm and have been dried.

In accordance with the present invention, the addition of a bed of paper powder to the lining material reduces the time required to heat the composition after applying it to the walls of the container, for example by a slinger.

The addition of carbon black, graphite or ground coke gives the composition properties that better resist chemical attack by molten metals.

The proposed material has a brittle consistency for use and is suitable for application by a slinger.

The natural triglyceride oils used to prepare the proposed material are composed of so-called resin oils, i.e. liquid fats consisting mainly of mixed glycerol esters of higher fatty acids with an even number of carbon atoms, and so-called drying oils, i.e. a few unsaturated bonds. It is a liquid fat with a high proportion of fatty acids.

Examples of such natural triglyceride oils are vegetable oils such as:

These are soybean oil, blown soybean oil, steamed soybean oil, linseed oil, corn oil, poppy oil, rapeseed oil, safflower oil, olive oil, cottonseed oil, peanut oil and tung oil.

Examples of animal triglyceride oils are NiQ oil, cod liver oil,
Sardine oil, oil and various fish oils such as whale oil.

These natural triglyceride oils can be subjected to a pretreatment such as steam blowing as carried out in Blown Soybean Oil 1.

The triglyceride oil may also be subjected to conventional treatments such as Fuller's earth treatment or deodorization.

In the above examples, linseed oil, soybean oil and safflower oil are considered drying oils.

Soybean oil, particularly deacidified and bleached soybean oil, has been found to be particularly useful for incorporating into materials according to the invention.

Such soybean oil does not cause environmental pollution such as release of odors.

Soybean oil has a flow temperature of -10 to -16°C (Ubbelohde process) and a flash point of 282°C (German Standard No. 7732-1).
page).

Of course, instead of just one triglyceride oil, a mixture of several triglyceride oils can be added.

Triglyceride oil must be liquid at a temperature of 10°C.

The invention is illustrated by the following examples.

Example 1 35% by weight of particles with a particle size of 0.09 mm or less and a particle size of 0.09
1000 Kp of calcined dolomite mixture containing 65 weight soybeans in 3 dishes was placed in a heated mixer at 180°C.

Four weights of the finished composition of commercial soybean oil were sprayed by nozzle into the moving mixture.

Mixing was continued until a crumbly composition was obtained.

Then finely ground 2.0% phosphoric acid) I
J-Kum is finely ground 0.5 weight silicic acid)
IJ cum (particle size <0.09 mm) was added as an inorganic binder and mixing continued for an additional 4 minutes.

Total mixing time was 12 minutes. This composition was applied by a slinger to the inner wall of a crude steel ladle to form a wear-resistant lining.

Mixing can also be carried out at room temperature in a cold mixer.

A second batch of mixed composition was stored sealed for 3 months.

At the end of this storage period, the composition was found to be just as satisfactory to use as a freshly prepared composition.

Example 2 The preparation method described for Example 1 was repeated once, except that bleached deacidified oil was used in place of regular soybean oil.

Claims (1)

[Scope of Claims] 1. A refractory lining material comprising calcined granular dolomite as a base material and organic and inorganic additives, containing 1 to 6 parts by weight of natural triglyceride oil or a mixture of triglyceride oils and 2 to 6 weight pieces of dried and ground rice)
Lining material for containers containing molten iron or steel, characterized in that it contains silicates or phosphates of IJum or potassium or mixtures of these salts. 2. Lining material according to claim 1, characterized in that it contains 0.5 to 3 parts by weight of paper powder as an organic additive. 3. Claim 1, characterized in that the inorganic additive contains carbon black, graphite, crushed coke, or a mixture thereof in an amount of 1 to 3 by weight.
Lining materials listed in section. Lining material according to claim 1, characterized in that it contains 42 to 4 kg triglyceride oil. 5. Claim 1 or 4, characterized in that the triglyceride oil is vegetable triglyceride oil i.
Lining materials listed in section. 6. The lining material according to claim 5, wherein the triglyceride oil is soybean oil. Lining material according to claim 2, characterized in that it contains paper powder of 71 to 2 kg by weight.