SE466296B - PROCEDURES FOR THE TREATMENT OF RESTMESA, RECOVERY OF RECOVERY OF COOKING CHEMICALS IN THE CELLULOSA INDUSTRY - Google Patents

Description

466 296 10 15 20 25 30 35 2 the transport route where it constitutes a troublesome environmental problem. The residual mesan is also an environmental problem on the tips where it is deposited, which is why these tips must have special permits from the authorities.

Brief description of the inventive concept The present invention aims to eliminate the above-mentioned inconveniences in connection with the handling of residual mesa from the chemical recovery of the cellulose industry and to create conditions for a simple, smooth and environmentally friendly handling thereof. This is achieved in accordance with the invention in that the residual mesane is mixed with a desiccant in the form of soot in a mixing ratio in the range 1: 2 to 1: 4, suitably in the ratio 1: 3 calculated in volume units, the soot sucking up liquid from residual mesane and together with it forms a dry, particulate and / or granular mixture product. Advantageously, the soot obtained as a residual product can be used in the firing of effluents in the boiler housing or a solid fuel boiler.

The handling of such soot today also takes place in such a way that the same is collected in a container that is emptied regularly. However, this container is located outdoors. The soot is volatile and has a certain tendency to "dust". Soot, therefore, like residual mesan, also constitutes an environmental and management problem within the relevant industrial area.

By mixing residual mesa and soot in the manner prescribed according to the invention, a product is obtained in the form of both particulate and granular constituents (with a largest grain size of about 25 mm) and with a dry consistency which makes the product easy to handle and hot transport in and in that it has no tendency to stick to the surfaces, for example on a truck bed.

In practical experiments, a volume part of residual mesa with a volume weight of 1.90 tonnes / m3 has been mixed with 3 volume parts with a volume weight of 0.70 tonnes / m3, which gave a mixing product with the above-mentioned properties. It obtained with S01 ". 10 15 20 '25 30 35 466 296- 3 an earth-like appearance and a consistency reminiscent of so-called industrial soil. The color was brown / black and the product was practically odorless. larger proportion of residual mesa, namely such a large proportion that the mixing ratio became greater than 1: 2, the mixture product became sticky and viscous. 4, a mixture product was obtained which was so dry that the "dusted", ie dry soot constituents were easily released from the mixture and carried by the air.

The mixing ratio between residual mesa and soot should thus be substantially 1: 3, although satisfactory results can also be expected in the range 1: 2 to 1: 4.

Further elucidation of prior art Through SE patent 78493 it is previously known to treat mesa by mixing it with a desiccant. The starting point for the said patent has been that the mesa was considered to be a practically worthless waste product, which could not be utilized in a satisfactory manner and which caused costs and inconveniences in connection with its removal.

Based on this starting point, the patent presents the idea of regenerating the lime content of the mesa by firing, after it has been partly dried and partly formed into brick-like pieces suitable for firing.

In connection with this, the mesa is dried, possibly by adding special drying agents. Examples of such drying agents are mentioned in the description of the patent (see page 2, column 1, bottom rows) such materials as powdered coal or coke, peat or sawdust.

Common to all these drying agents is that they constitute combustible materials, ie materials which have an intrinsic value insofar as they contain combustible substances from which heat energy can be generated.

That the materials in question should be combustible is stated in the description of said patent as a prerequisite 466 296 10 15 20 25 30 35 4 for the reason that they should be able to be burned during the burning of the mesa and thereby contribute to the generation of the temperature required for carrying out the firing.

In addition, the materials should give an increasing porosity of the mesa pieces as their combustion progresses. The patent also mentions the possibility of mixing a per se non-combustible material, namely lime flour, apparently for the purpose of increasing the lime content of the burnt end product. The patent in question is thus the origin of the mesa combustion that is routinely applied in today's chemical recycling technology.

The present invention is based on a completely different problem than the one on which SE 78493 is based, namely to make the residual mesan easier to handle and transport. In addition, the invention constitutes a problem solution which is essentially different from the problem solution according to SE 78493, in that soot is a material which has no intrinsic value insofar as it, in contrast to coal, coke, peat or sawdust, is a combustion product which is no longer combustible. Thus, in the invention, it is not an object to provide a combustible mixing product, nor a mixing product with elevated lime content with the intention of regenerating it.

On the contrary, the aim is to enable the smooth and easy handling of residual mesa at the lowest possible cost and to that end, as expressly prescribed in the following claims, soot and nothing else is used, more specifically soot mixed with residual mesa in a mixing ratio in the range 4: 1 to 2: 1, preferably in the ratio 3: 1 calculated in volume units.

It is a given that the product obtained by the invention can be used and further processed in different ways. Thus, it is conceivable to use it as a soil extender, the use of the agent on acidic soils becoming particularly interesting in that the mixture is markedly alkaline due to its sodium and calcium content. Further processing of the product can take place, for example, by mixing in peat, bark, sawdust or the like, for example in connection with the use of the product as a soil extender.

Claims (1)

1. 466 296 6 CLAIM PROCEDURE Process for treating residual mesa, obtained from the recycling of cooking chemicals in the cellulose industry, which residual mesa tends to adhere to surfaces of various kinds due to its tackiness, characterized in that the residual mesa is mixed with a desiccant in the form of soot in a mixing ratio in the range 1: 2 to 1: 4, suitably in the ratio 1: 3 calculated in volume units, the soot absorbing liquid from the residual mesane and together with this forming a dry, particle and / or granular blend product. 15 20