DE1792120C - Process for the electrostatic processing of kieserite-containing crude potash salts - Google Patents

Description

30th

Potash fertilizer salts with MgO content are used for the additional supply of soil and cultivated plants increasing importance with magnesium,; ι $ especially as pasture manure.

No process is yet known which enables the joint extraction of sylvine and gravelite in a single production run from crude potassium salts containing kicscrite, such as hard salts. In the majority of all processing methods, the kieserite ends up in the residue with the rock salt, so that in order to produce _{fertilizers containing K 2} O and MgO, the sylvine must first be separated, then kieserite extracted from the residue and then both components must be mixed . It is also possible to separate Kiescrit first and then Sylvin. However, two separate process steps are always necessary in order to obtain both minerals.

Several methods are known for the separate extraction of both substances, e.g. B. by means of electrostatic processes. It now became a procedure found for the electrostatic processing of kieserite containing crude potash salts, which thereby is marked that the ground crude salt

Momerungsmm; ^ tahandet ^ ^ ^

charge of the K-icscrits oe _Hi i _fskond jiionierun!: N glcichze.uge A " ^wcn ^ ^nß _ar ^ atic carboxylic acids by means of together nut aro ^ _jn

as a conditioning _agent wr y lvinhahlg, _n same separation emes * ™ «\» _Vi J _{c and} a PRESENT-free rock salt an de,

matted first,

15% egg

will.

and a Μ ^ ΛβΙ from _Fc

wcsc from 5 to 15 A ^ gnge «^ _by V ^ onÄcuchtc of about 5 to 30% to a K ₂ O content of about 1J ta ^ BΛ and an MgO content of about 2 to 20%, preferably : vnn S can be set to 15%.

From hard salts as crude potash salt α of a Vcr? Ah ^k rensstu ^U fe an MgO-containing Kaljdünge ^ h ^ -in Kic iri ° / KO and about IU 01s ζυ / ο iv

with over 95%, especially over

technical progress of the process of

SfrSSTicli W * '«" * ■ * ^{5 to} 10% tea »" «moisture in the dryer lutt

ehend 57 bl 73-C at 12 g / m 'absolute "air pollution". accomplished.

table

I conditioning agents 2. auxiliary conditioning agents

1. o-cresotic acid

2. 1.

2. monochloroacetic acid

Κ, Ο content

% Concentration and residue

45.0

11.1 , 6

11.8

Ambeutea in Kooz. to% K ₂ OI kieserite

87.3

continuation

1 ₄

I conditioning agents 2. Auxiliary conditions mill

1

?. / '- bromopropionic acid

1. -

2. Trichloroacetic acid

1. o-cresotinic acid

2. monochloroacetic acid

1. Benzoic acid

2. monochloroacetic acid

1. o-Crcsotinic acid

2. / i-bromopropionic acid c

1. o-cresotinic acid

2. Trichloroacetic acid

KjO-Gehali

11.0

8.8
24.5

23.4
27.7
24.3

Kirscnl content Residue d Kiescrit It concentrate 7.4 Yields in Koni in % 89.6 backlog 46.2 6.9 K ₂ O 83.6 10.0 56.2 5.1 - 89.3 11.5 54.8 5.3 87.8 1.9 62.0 5.7 89.8 88.5 2.6 52.9 4.4 86.5 90.6 1.4 56.2 92.0 1.7 88.4

Experiment No. 1 shows the state of the art with o-cresotinic acid as a conditioning agent. Experiments No. 2 to 4 show the effect of the auxiliary condensing agents used according to the method of the invention on the charging behavior of the Kicscrit. Experiments 5 to 8 show the combined use of the known conditioning agents for sylvine and older stressed hip conditioning agents, the chemical compounds mentioned as the second substance being the auxiliary conditioning agents claimed. Columns b and c show the K ₂ O and kieserite contents in the concentrate and residue and column d shows the yield in% in the concentrate.

The residue consists of rock salt with over 90% NaCl, which is a coupled product door itself can be used, especially as a starting product for the production of pure NaCl.

The NaCl content of the residue from Table 1 are the following:

No. %
No. % 1 68.9 91.9 2 75.3 6th 90.6 3 76.8 7th 92.1 4th 74.9 8th 92.9

Procedure 1 was carried out according to the prior art and shows that sylvin is on the positive cone. .-ntrat-electrode cringes. The kieserite accumulates together with the rock salt on the negative residue electrode. The rock salt content in the concentrate and residue results approximately from the difference to 100%. So you get a concentrate with 45% K ₁ O and about 3% MgO, corresponding to 17% kieserite. If z. If, for example, a calcium salt with 20% K ₂ O and 15 to 20% MgO is to be produced, then kieserite would have to be separated from the residue using the procedure in Auslegeschrift 1 261 453 and combined with the KJO concentrate.

According to the process of the invention, it is therefore possible for the first time to reload kieserite using halocarboxylic acids as auxiliary conditioning agents, as the procedure according to FIGS. 2 to 4 shows. Kieserite is then obtained from the positive concentrate electrode.

If both conditioning agents are combined according to procedure 5 to 8 , in particular sylvine and kieserite are separated together at the positive concentrate electrode. In a '' process step, an MgO-containing potash fertilizer salt with around 25% K ₂ O and 16% MgO is produced.

The process of the invention according to procedure 5 to 8 further offers the advantage of a high yield of about 90% K ₂ O and MgO.

Table 2 shows the joint recovery of sylvine and kieserite at separation temperatures between 36 and 76 ° C, corresponding to 5 to 30% relative humidity in the warming air. The processed goods will

so tuit about 50 to 200 g / t of an aromatic carboxylic acid, preferably with 75 to 125 g / t and about 25 to 200 g / t of a halocarboxylic acid, preferably with 50 to 150 g / t, conditioned. Hereinafter Example (Table 2) 100 g / t 6-Hydroxy-O-toIyl-

acid-0) and 75 g / t monochloroacetic acid are used as conditioning agents. With a single pass through a free-fall separator at 4 kV / cm, the following results were achieved:

a b ( table Residue 2 t • Residue t Kiesent temperature relative splendor 7.0 9.5 Yield in V »
in concentrate 82.5 '" No. ⁰ C % KjOGcbalt
V. 1 K ₂ O «4.7 36 30th concentrate Kieserite content
% 57.7 9 45 20th 20.0 concentrate 88.2 10 24.8 43.7 55.7

a b continuation Residue ( I. e Kiesenl temperature relative humidity 1.9 Kieserite -Salary Yield in · '·
in the central 87.4 No. "C % K, O content
V. 1.7 concentrate Return K, O 88.4 50 15th concentrate 1.7 56.0 5.8 89.3 85.8 11th 59 10 26.7 59.0 5.2 90.1 i2 76 5 29.2 30.2 15.9 88.7 13th 39.7

Column a of the table shows the temperature, column b shows the temperature. The enrichment product of the second separator, the corresponding relative humidity of the heater, is circulated in continuous operation, columns c and d show the K ₂ O content and 15 stirred, the kieserite content in the concentrate and residue, Table 3

and column e the yield in% in the concentrate Air Sylvin and Kiescrit.

The residue consists of rock salt with the following NaCl contents:

No. % 9 79.4 10 • 89.6 11th 91.2 12th 92.1 13th 81.4

Salary in·/. Shares in% Kicserite KjO Kicserite K ₃ O 100 Task ..... 11.2 26.8 100 96.7 Concentrate .. 20.0 43.5 98.3 3.3 Residue ... 0.4 2.2 1.7

The results are special at high relative humidity and correspondingly low temperatures Cheap. The heat consumption is therefore low.

In a single pass, high-quality fertilizer salts with 20 to 29% K ₂ O and 15 to 17% MgO with K ₂ O yields of 88 to 90% and MgO yields of 85 to 88% can be produced.

Table 3 shows the joint K ₂ O-MgO recovery at 47 ° C, corresponding to 15% relative humidity in the warming air.

The salt was treated with 100 g / t 6-Hydroxy-O-tolylic acid- (I) and 75 g / t trichloroacetic acid. In order to obtain sylvine and kieserite almost quantitatively, the residue from the 1st separation was without Post-conditioning to a second separator

The NaCl content in the residue is 97.2%.

Thus, a MgO-containing potash fertilizer salt with 20% K ₂ O and 15% MgO is obtained with a yield of 98% for sylvine and 97% for kieserite.

This result of the process of the invention represents a leap forward over the prior art. Another advantage of the process of the invention is that a high throughput of crude salt is possible, with practically no or only a small amount of medium. It is also possible to subsequently split the K ₂ O-MgO concentrate into sylvine and kieserite. This subsequent separation into Sylvin and Kiessrit also has advantages, since the larger amount of rock salt is separated off as a residue and only the smaller amount of K ₂ O-MgO concentrate has to be processed. According to known methods, on the other hand, either sylvine or kieserite is separated in the first separation step and the subsequent separation stage is added with the entire amount of rock salt and kieserite or with the entire amount of rock salt and sylvine

Claims (3)

Patent claims: '.. Process / ur electrostatic processing of kiescrit containing crude potash salts, characterized in that the ground crude salt mixture is treated with halocarboxylic acids as auxiliary conditioning agents, which cause a reversal of the Kicserite and that by the simultaneous use of the auxiliary conditioning agent together with aromatic carboxylic acids as a conditioning agent for sylvine joint deposition of a concentrate containing kieserite and sylvin on the positive electrode and a K ₂ O-poor, practically kieserite-free rock salt on the '5 negative electrode. 2. The method according to claim 1, characterized in that the separation at about 10 to 20% relative humidity in the dryer air, corresponding to 45 to 59 ° C at 12 g / m ³ absolute μ humidity, in a free-fall separator at 4 kV / cm field strength , is carried out. 3. The method according to claims 1 and 2, characterized in that the K ₂ O-MgO ratio of the concentrate by adjusting the as Trennblendc to a KJO content of about 15 to 40% and an MgO content of 5 to 15% is set.