DE30209C - Process for the preparation of alkali silicates, alkali carbonates, hydrochloric acid and chlorine - Google Patents

Description

IMPERIAL

PATENT OFFICE.

The invention consists in the decomposition of chloralkali (especially sodium chloride and potassium chloride) by treating them with silica in statu nascendi, which is produced by oxidizing the silicon contained in the molten pig iron with an air blower and steam.

That which is necessary to bring about the reaction Heat is supplied by the molten pig iron, which is produced by combustion the silicon is heated very strongly.

In this way, alkali silicates, hydrochloric acid and chlorine are produced. '

All attempts made so far to decompose the salt with silica have been unsuccessful, in fact:

ι. because sand and quartz, which are much less effective than silica in siatu nascendi, were used;

2. Because it has been recognized commercially and technically as impossible to generate the heat and to maintain what is necessary to secure the reaction;

3. Because the manufacture and maintenance of an expensive special apparatus is necessary became;

4. Because it was impossible to have even close enough intimate contact between the salt and the silica.

All of these deficiencies are eliminated by my invention. When running my Invention is proceeded as follows:

I use a Bessemer pear or a gas oven (preferably a Siemens oven) that is lined with a neutral or siliceous, fire-resistant layer. Of the Operation with a Bessemer pear is the following:

As a reagent I use a pig iron, the silicon content of which is as high as possible, am preferably over 4 pCt., and that contains as little carbon as possible.

In the heated converter I first put some of the salts mentioned in the form of heavily pressed or cast blocks or cylinders, after the salt is best before with iron or manganese oxide, or with magnesia or with lime, that as Sometimes a bit of calcium chloride is added to the binder.

It can also evaporate too quickly by covering the salt with a cast iron plate or such a coating can be prevented.

The remainder of the salt is introduced into the fan through the nozzles. The melted one silicon-rich iron (ferrosilicon), with which the salt is treated, is found in the Converter brought and exposed to the ordinary blower.

However, I use the fan, preferably through a funnel, to guide the regulation the supply of the salt is provided with a screw, add another amount of salt, so that the total amount of the added salt is at least equal to five times the weight of the Is silicon, which is contained in the pig iron used.

I also introduce steam into the metal bath through the air or through a special nozzle, which overheats ^{to at least 300 ° C.}

will; I also think it's beneficial to overheat the fan.

A part of the salt can be introduced with these steam jets, which are best under very high pressure. The Gesammtgewicht of added steam should be carried out of the silicon in the pig iron used is generally more than _{^2/3 of} the weight; the quantity of steam, however, must be so regulated that the bath does not cool too much.

If there is much carbon in the pig iron, the steam supply must be reduced because much heat is absorbed by the action of carbon on steam and the Operation is held up.

If the metal bath shows signs of cooling, the process is interrupted and the Discharged slag, which consists essentially of sodium silicate with a little iron oxide. The metal itself is obtained by the process common in steelworks, namely either in the same or in a different converter, or in a Siemens furnace.

It has been found beneficial to stop the operation, drain the sodium slag, before all the carbon is burned, and in some cases the sodium slag Immediately drain as soon as the carbon burns briskly, which is observed through the spectroscope can be.

If there is also phosphorus in the steel, it is best to use another converter or Oven removed.

The operation with a gas stove is mutatis mutandis exactly the same as it has been described for a Bessemer pear:

Part of the salt (which, as mentioned, is properly protected from volatilization) placed on the stove top before the batch is introduced, and the rest through introduced a movable air nozzle, which I put in the oven for this purpose.

As previously described, superheated steam is also blown in.

The steam and air nozzle (because steam and air can be introduced through the same nozzle are to be arranged so that they are under the salt as far as the lowest part of the hearth can be performed, which is thereby stirred well and mixed with the metal bath will..

When using a gas oven it is often advisable to put a layer of salt on it unfired. Covering limestone so that the volatilization of the salt is prevented more effectively will.

If all of the salt appears to have been transformed, the slag is drained off. It also exists here mainly from sodium silicate. The same is done by leaching or by other devices separated from the added iron oxide and either sold as such or by treating with carbonic acid under pressure converted to sodium carbonate.

During the process, hydrochloric acid and chlorine are released and can thereby can be obtained by passing the gases through condensers or other means of Catching applies.

Claims (2)

Patent-to sayings: 1. The production of alkali silicates and finally alkali carbonates, as well as of Hydrochloric acid and chlorine by treating the alkaline chlorides in a Bessemer pear, a reverberir or other oven with air and steam in the presence of molten silicon-rich iron (ferrosilicon). 2. In the process for the preparation of alkali metal silicates from chlor-alkali the one described Device to prevent the too rapid volatilization of chlor-alkalis, consisting in pressing or melting the same in blocks or cylinders with or without admixture of lime, magnesia, and iron oxide or manganese oxide to ensure their more complete decomposition.