DE1076593B - Process for the electrostatic processing of potash salts - Google Patents

Description

GERMAN

So far, very few processes for the electrostatic processing of potash salts have become known. One of these methods (British patent specification 723 477) works without the addition of reagents only with heating the material to be processed to fairly high temperatures (300 to 700 ° C), to the the electrostatic separation follows after cooling to temperatures between 38 and 218 ° C. Because the high heating costs and the fact that this method is only good for certain types of salt Delivers results, but with others it produces unsatisfactory or useless results do not enforce this practice in practice.

Another group of processes works with the addition of reagents (German patents 970 953, 948 861), and that such reagents are used in close association with the flotation process, which are used in the Flotation is known either as a collector for the potash salts concerned (aliphatic amines plus branched-chain Alcohols) or have a lattice analogy with the potash salt concerned and are epitaxial can be adsorbed. In both cases, the intention was to selectively influence certain factors Components of the goods to be processed.

It was only through the most recent investigations that it was established that the path of selective coating one or more components with conditioning agent appears to be incorrect. In the German patent 1,056,551 could be shown that a large class of substances, namely organic sulfates and sulfonates, which are only a subordinate part of the flotation of sylvine or, like the sulfonated dyes, play no role whatsoever as a conditioning agent for the electrostatic treatment of Processing goods containing Sylvin are ideally suited. The type of conditioning (spraying, Mixing, swirling in a gas stream loaded with conditioning agent) entails that apparently all components of the goods to be processed are in contact with the conditioning agent come, so that from a selective influencing of a component or group of components not the Can be talked about. The results obtained by this process were so surprising and so excellent that that it seemed advisable to continue working on this path.

The relevant investigations have now shown that a further, very large class of organic substances as conditioning agents for the electrostatic separation of sylvine should be placed alongside the organic sulfates and sulfonates, namely the carboxylic acids with at least 3 carbon atoms in the molecule . Surprisingly, it has been found "that the size and the che method for electrostatic
Processing of potash salts

Applicant:

Potash Research Institute G. mb H.,
Hanover, Georgstr. 29

Dr.-Ing. Hans Autenrieth, Hanover-Kirchrode,
has been named as the inventor

The mixed character of the remainder of the molecule obviously only plays a subordinate role, the fact that it is of the aliphatic, belong to cycloaliphatic, aromatic or hydroaromatic series, saturated or unsaturated and also with other functional groups, for example with other carboxyl groups and / or sulfo groups may be substituted. Furthermore, as orientating experiments showed, the carboxyl groups also be fully or partially esterified. They are excellent representatives of the claimed class the fatty acids, naphthenic acids and carboxyl group-bearing dyes such as "below the given examples.

Exceptionally good results can also be achieved if you use the carboxylic acids - like the whole claimed class is mentioned below for the sake of brevity - in a mixture with that from the German Patent specification 1,056,551 uses known sulfonates, as also demonstrated by an example will. Mixtures of carboxylic acids are also effective

909 758/89

The proposed method is that the dry material to be processed a conditioning with the substances proposed here and then at a suitable temperature in the electrostatic precipitator is separated. The conditioning agents 5 are generally used in amounts of 50 to 300 g / t Reprocessed goods applied; in special cases, however, considerably smaller amounts are sufficient than 50 g / t.

Conditioning takes place by bringing the reagent into contact with the material to be processed by mixing, spraying, whirling up in a gas stream that is loaded with the conditioning agent is, by dusting, or by any other known method, the reagent in substance or can be used in dissolved or emulsified form.

The solvent or dispersant must be removed again before the electrostatic separation.

Then you bring - if necessary - the items to be processed to the separation temperature, which is preferably between 30 and 80 ° C. Is it from any Reasons desirable to carry out the separation at a higher temperature, for example because that Processing material comes out of the drying system at a higher temperature, then it is easily possible the separation can also be carried out at temperatures up to 200 ° C. In any case, the the most favorable separation temperature according to the type of conditioning agent used and is determined by experiment easy to determine.

It has been shown that a small variant improves the separation results significantly in certain cases. This variant consists in that the material to be processed after it has assumed the separation temperature is not given immediately via the separator, but initially by preferably 10 to 30 ° C is cooled and then reheated to separation temperature.

The particular advantages that the use of the mentioned class of substances brings with it lies in two Well-founded facts: Some of these materials are very cheap because some of them are waste materials or Acts by-products without sufficient technical possibilities of use. Further only be very small quantities of the order of about 50 to 300 g / t of processing material are required.

Examples

The results compiled in the following table were all obtained with the same crude salt, a sylvinite with 15% K ₂ O, at a separation potential of 3 to 9 kV / cm.

As Table 1 shows, equally good results are obtained when using uniform substances as well as mixtures, the effects of the first run fatty acids are particularly noteworthy, which as cheap waste products have so far not found any technical use. Alizarin yellow GG (Schultz's color tables No. 55), eosin (Schultz dye tables No. 881) and uranine (Schultz dye tables No. 880) are carboxylic acids of the aromatic series.

The results obtained with uranine and humic acid appear particularly in terms of the yield in comparison with the other substances as unsatisfactory. At least they do compared to the previously known · process for the electrostatic processing of sylvin-containing Mixtures represent considerable progress.

Table 1

lot Separating
tempe
rature K ₂ O-
The end-
prey Conc joined Conditioning
middle a
malignant
Nadi- g / t ⁰ C «/ 0 focus 2 3 4th tration »/ 0K2O 1 5

Linseed oil fatty acid

First run fatty acid mixture C ₃ to C ₁₀

Fatty acid mixtures ί
C ₇ to C ₁₂ j

Oleic acid

Ricinoleic acid

Oxystearic acid.

Alizarin yellow GG ..

Eosin

Humic acid

Benzoorange R,

Dye table

# 404

Glutamic acid ....

Shellac ~ r, _._......

Linseed oil fatty acids ..
Oxystearic acid.
Main run fatty acid

C ₁₂ to C ₁₈

Uranine

Naphthenic acids,

raw

Benzoic acid

p-toluic acid

Phenylacetic acid ..

Cinnamic acid

Salicylic acid

Acetylsalicylic acid

Phthalic acid

Phthalic acid

Phthalic acid

Phthalic acid .......

Phthalic acid

Rhodamine 3 B extra,

Dye table

No. 867

Glycocolla dodecyl

ester

margarine

olive oil

100 60 96.5 100 40 95.3 75 35 94.9 150 60 93.2 150 60 91.5 75 120 93.0 100 50 83 100 40 90.6 75 40 89.8 150 60 92.1 150 60 90.7 150 60 67.3 150 80 90.9 150 50 91.5 150 50 93.3 150 50 96.5 150 50 89.8 150 50 94.7 150 60 78.2 150 50 89.8 150 50 93.3 150 50 86.4 150 50 94.0 150 50 93.3 150 50 92.0 150 50 84.4 5 50 85.6 19th 50 90.0 37.5 50 88.4 75 50 91.5 150 50 86.3 150 50 88.8 150 50 72.6 150 50 92.3 150 50 86.8

53.3 54.1 59.2 55.8 55.6 55.0 53.5 53.1 51.2

53.8 55.0 40.0

48.5

52.2

55.0

53

51.2

53.4 47.4

55.7 53.2 59.2 58.0 58.5 51.5 47.9 41.4 53.6 56.5 58.4 59.5

55.8

50.0 48.8 47.9

This table could be expanded as desired by further examples of substances of the proposed class will be, but it will be dispensed with, since it would not result in any new points of view.

Table 2 shows the influence of the intermediate cooling. The yield was while working in the same way as in the examples in Table 1, after a one-time post-concentration only 71.5%. But after heating to 50 ° C it was first cooled to 20 ° C, heated again to 50 ° C and only then divorced, so one received under otherwise the same

Chen conditions a K ₂ O yield of 91.4%. The concentrate level was the same in both cases.

Table 2

Conditioning
middle lot
g / t Separating
tempe
rature
⁰ C K ₂ O-
The end-
prey
° / o Con
centrate
¹ VoK ₂ O Whale oil fatty acid
mixture 100 50 71.5 *
91.4 * 53.7

of carboxylic acids as conditioning agents, the dust content of the material to be processed (proportions of grain sizes below 0.1 mm) has no significant influence on the separation results, as is shown in Table 5 below, which was obtained from a hard salt containing 150 g / t of first-run fatty acid C ₃ to C ₁₀ conditioned and at 60 ° C

10

_{3 10}

was electrostatically separated.

Table 5

* Explanation in the text.

Table 3 below shows the results obtained with a mixture of Na alkylsulfonic acid (»Mersolat«) and a pre-run fatty acid mixture were achieved, the mixing ratio being alkylsulfonic acid Na: fatty acid = 1: 1. For comparison, the results for Na alkylsulfonate are entered alone and fatty acid alone.

Table 3

Dust content
(-0.1 mm) yield Concentrate% K ₂ O 2nd round »/ 0 ° / o K ₂ O 1st round 60.8 0 91.0 47.3 60.3 2 92.7 38.5 60.5 4th 94.1 42.8 60.3 7th 91.3 41.0 60.5 10 90.5 37.6 59.8 14th 90.0 41.7

Conditioning agents

Fatty acid mixture C ₃ to C ₁₀
Alkyl sulfonic acid Na
(»Mersolat«)

Alkyl sulfonic acid Na

(»Mersolat«) + fatty acid mixture

150 150

150

93.0 92.5

92.3

Concentrate VoK ₂ O

54.0

55

59.7

It can be seen that with the same yield, the concentrate level is due to the simultaneous and common Use of the two conditioning agents has increased by almost 5 and 6%, respectively.

_{The following example in Table 4, which shows the results obtained with a hard salt with 12% K 2} O, shows that the process proposed here is not restricted to sylvinites, but can be used for all sylvin-containing processed goods.

Table 4

Conditioning agents

Main run fatty acid

C ₁₄ to C ₂₂

First run fatty acid

C ₁₃ to C ₁₀

Naphthenic acid,
least

Naphthenic acid, crude

Phthalic acid

Salicylic acid ......

Cinnamic acid

margarine

Benzoic acid

As with the one before
of sulfonates also have

Separating K ₂ O- lot tempe The end- rature prey g / t ⁰ C «/ 0 150 60 94.7 150 40 94.0 200 50 90.8 200 50 85.4 200 50 91.3 200 50 96.2 200 50 95.3 200 50 92.3 200 50 90.6

53.4 54.0

49.0

50.0

50.2

48.4

50.0

53.7

56.0

specified use here when using

65 The fact that compounds in which the KCl is not in free form, but bound as a double salt, such as in carnallite (KCl-MgCl ₂ -OH ₂ O). The following table 6 summarizes the results that were achieved in the preparation of a carnallite crude salt. The crude salt had a carnallite content of 52%. Conditioning was carried out with 150 g / t of the fatty acid mixture C ₃ to C ₁₀ (first run fatty acids). The separation temperature was 60 ° C. It goes without saying that the melting temperature of 167.5 ° C. must not be exceeded during the carnallite processing.

Table 6

45 concentrate
Medium good ..
Residue .

Carnallite content (° / o)

91.5

48.1

3.2

K ₂ O quantity ° /

77.2 14.8

92 Vo yield

concentrate

⁰ ZoK ₂ O

Claims (2)

PATENT CLAIMS: 1. Process for the electrostatic processing of potash salts (crude salts or intermediate products the potash industry) with prior chemical conditioning of the material to be processed, characterized by conditioning with carboxylic acids with at least 3 carbon atoms of the aliphatic, cycloaliphatic, aromatic or hydroaromatic series, their salts or esters, those in the molecule also have further carboxyl groups and / or sulfonic acid groups and / or can carry other functional groups. 2. The method according to claim 1, characterized in that the carboxylic acids as uniform Substances or as mixtures either of carboxylic acids among themselves or of carboxylic acids with other than conditioning agents for the electrostatic treatment of sylvin-containing Well-known substances, for example the organic sulfates or sulfonates or their mixtures, come into use. - »9 758/89 2.