SE423534B - MASS ON BASIS OF BREND, CORNED DOLOMIT AND WITH ORGANIC AND INORGANIC ADDITIVES FOR INFO LINING OF CONTAINERS FOR MOLD STEEL OR IRON - Google Patents

Description

15 20 25 30 35 40 77i1zs7s-4. t '2 effectively prevent hydration, ie the exclusion of moisture from the air. Such pulps based on burnt dolomite, which contain the usual, known, organic additives, are therefore not storable for a long time. Apart from the possible prolongation of the shelf life through mineral oil and fatty acids, the basic masses based on dolomite, such as magnesia, contain in all the patents mentioned here * additives of tar or pitch, which when added to these masses means a considerable inconvenience in form. of smoke or odor. Additives of inorganic binders are not mentioned. The object of the invention is to provide pulps based on burnt dolomite, which can be stored for a longer period, for example three months or longer, without significant hydration, ie the properties of the pulps are not impaired by absorbing moisture from the air. It has now been found that such pulps can be prepared on the basis of burnt dolomite with the grain structure adapted for the purpose of use and organic and inorganic additives, if a natural triglyceride oil or a mixture of such triglyceride oils and a dry, inorganic, malt is used as the organic additive. binder. .

The pulp according to the invention is characterized by a content of 1-6% by weight of a natural triglyceride oil or by a mixture yielding triglyceride oils and a content of 2-6% by weight of dry, inorganic, ground binder and optionally by an addition of paper flour and / or carbonaceous substances.

According to a preferred embodiment, the content of triglyceride oil amounts to 2-4% by weight. It is considered advantageous to use a vegetable triglyceride oil, especially soybean oil.

Furthermore, it has been found that an addition of 0.5-3% by weight of dried paper flour further improves the processability of the pulp according to the invention in the slung machine, since a rapid drying It is advantageous to allow: ni- Further addition after the introduction becomes possible. the batch of paper flour amounts to 1-2% by weight. batches of carbonaceous material in the form of soot, graphite, ground coke are possible. The above information regarding weight percentage is calculated on dry total mass.

The pulp according to the invention is used in a known manner, for example the finished pulp for throwing the ladle for liquid steel or iron is thrown through the sling head of the slunging machine 3 15 __ _ ”s, l_ fl .. _. “. at high speed from the top into the free space between the sideboard wall and the inserted stencil.

After completion, the stencil is removed. The pulp has such a large internal cohesive force that it retains its shape and has such a high raw strength that it can also withstand transport for further processing, for example the road to the ladle burner, without damage.

The measured value with the standard impression depth measuring device according to Fischer is above 90. The prepared ladle is then heated and sintered through the first filled liquid steel or iron melt.

The pulp used according to the invention is recovered from burnt dolomite from any naturally occurring dolomite by conventional firing and subsequent crushing and / or grinding and, if necessary, grinding of grain fractions and cutting of grain fractions.

By the term dolomite is meant not only a substance with the chemical composition CaCO 3 ° MgCO 5, but also materials in which the quantitative proportion of CaCO 3 and MgCO 3 is subject to larger fluctuations, further materials in which a part of magnesium in the dolomite is replaced by iron or manganese. Thus, for example, dolomite with 54.5% CaCO 3 and 42.8% MgCO 5 and dolomite with 3.9% CaCO 3 and 89.22 MgCO 3 are known as natural minerals.

The grain structure of the fired dolomite used according to the invention for the production of the pulp should be such that 55% has a grain size below 0.09 mm, ie has the consistency of flour, and the remaining 65% has a normal grain structure of 0.09-4 mm or up to 6 mm.

Of course, the upper limit of the grain size can be 2 or 3 mm. It is advantageous that the proportion of the grain fraction below 0.09 mm is up to 50%.

The binder used in the compositions according to the invention may be, for example, dry, ground sodium or potassium silicate, sodium binder or potassium metaphosphate or a mixture thereof. that the binder is added in an amount of 2-6% by weight. the agent is preferably an inorganic, water-soluble substance. the positioning of the pulp according to the invention can take place in any known method of mixing the dry constituents. For example, first the burnt dolomite and the dry, ground binder can be mixed with each other and then the corresponding amount of the natural triglyceride oil is introduced. However, it is possible to first mix the burnt dolomite with the triglyceride oil, and then mix this mixture with the dry, ground binder, so that 10 β μm pß '30 o pouring oils are mentioned: f7713575-4 4, the triglyceride oil should preferably be deposited on the fired dolomite grains, to reduce the tendency to hydrate the burned dolomite. However, it is preferred to add the triglyceride oil and mix it in before any triglyceride oil is to be absorbed into the highly porous paper flour.

It is advantageous that the addition of the triglyceride oil is carried out with the addition of paper flour, so that the triglyceride oil, possibly after heating up to a temperature of 60 ° C to reduce the viscosity, is sprayed with a nozzle onto it in a mixer movable the mass of solid constituents, so as to achieve as uniform a distribution as possible and to avoid an unnecessarily long mixing time.

In the case of the paper flour, which may be added according to the invention, it is a matter of a shredded paper, which is shredded to a maximum fiber length of 1-3 mm and dried.

It has been found that by adding paper flour to the pulp according to the invention, the time for heating after the pulp has been applied, for example by means of a sling machine, has been reduced.

The addition of soot, graphite or ground coke creates a more favorable ratio of the pulp to chemical attack by the melt.

When the pulp according to the invention is in processable form, it can be crumbled and thrown by means of a sling machine. The natural triglyceride oils used according to the invention consist of the so-called fatty oils, i.e. liquid fats, which essentially consist of mixed glycerin esters of higher fatty acids with an even number of carbon atoms, and the so-called drying oils, i.e. liquid fats with a relatively high proportion of polyunsaturated fatty acids. As examples of such natural triglyceride oils, the following Soybean oil, blown soybean oil, linseed oil, corn germ oil, poppy oil, beet oil, safflower oil, olive oil, cottonseed oil, peanut oil, wood oil, etc. Examples of animal triglyceride oils are the various fish oils, for example herring oil, liver oil (cod), sardine oil, whale oil and horseradish oil§ These natural triglyceride oils may be subjected to a pre-treatment, for example a blowing, such as with blown soybean oil. Optionally, a conventional pretreatment of the triglyceride oil can also be carried out, for example a treatment with bleaching earth or an deodorant.

Of the examples listed above, linseed oil, soybean oil and safflower oil are among the drying oils. It has proved particularly advantageous in the pulps according to the invention to use soybean oil and in particular deacidified and bleached soybean oil, which in its use is environmentally friendly with regard to the development of smoke and odor. The soybean oil has a pour point of minus 10-16OC (according to the Ubbelohde method) and a flash point of 28Z ° C (DIN 7732, p. 1).

Of course, instead of a single triglyceride oil, a mixture of such triglyceride oils can also be used. The triglyceride oils must be liquid at a temperature of 10 ° C.

The invention will be explained below by means of the following examples: Example 1. 1000 kg of a mixture of fired dolomite with a grain size of 35% by weight less than 0.09 mm and 65% by weight between 0.09 and 3 mm are introduced in a mixer heated to 180 ° C. Then, by means of a nozzle, 4% by weight, calculated on the finished pulp (anhydrous), was sprayed on a soybean oil commonly used in the trade. After the spraying and mixing of the soybean oil, a mass with a crumbly consistency was obtained. To this mass were added as inorganic binder 2.0% by weight of finely ground sodium phosphate and 0.5% by weight of finely ground sodium silicate (grain size less than 0.09 mm) and mixing was continued for a further 4 minutes. The length of the mixing time was 12 minutes. This mass was introduced by throwing on the inner wall of a crude steel ladle as wear lining. The mixing can also take place at room temperature in a cold mixer.

A second part of this mass was stored for three months in a tightly closed room. After this storage time, it turned out that the stored pulp was as processable as freshly produced pulp.

Example 2. The procedure of Example 1 was repeated with the exception that instead of the normal soybean oil a bleached and deacidified soybean oil was used.

Claims (8)

1. 7713575-4 6 '' Patent claim ', .i_ _, _, W Mif' Pulp of Éasis of fired, granular dolomite and containing organic and inorganic additives for the lining of containers for molten steel or iron, characterized by a content of 1-6% by weight of a natural triglyceride oil or of a mixture of triglyceride oils and a content of 2-6% by weight of dry, inorganic, ground binder and optionally of an addition of paper flour and / or carbonaceous substances. of a lame Pulp according to claim 1, characterized by 2-4% by weight of a triglyceride oil. Pulp according to Claim 1 or 2, characterized by a content of a vegetable triglyceride oil. a Pulp according to claim 3, characterized by a content of soybean oil. Pulp according to any one of the preceding claims, n a d of a content of sodium or potassium silicate and / or sodium or potassium metaphosphate. 7 7 Pulp according to any one of the preceding claims, n a d of an addition of 0.5-3% by weight of dried paper flour. k ä n n e t e c k n a d of an till- k n n e t e c k Ä k ä n n e t e c k - _ Pulp according to claim 6, batch of 1-2% by weight of paper flour. Pulp according to Claim 5, 6 or 7, of an addition of 1-3% by weight of carbonaceous substances. k n n e t e c k n a d k ä n n e t e c k n a d 9 @ Pulp according to claim 8, of an additive of soot, graphite or ground coke. WHY PUBLICATIONS: