DE1249783B - - Google Patents

Description

GERMAN WflTvSttS PATENT OFFICE

■ ^ ■ ^ German class: 1 b - 6

EDITORIAL ν — π

File number: W41178 Vla / lb

J 249 783 filing date: March 19, 1966

Opened on September 14, 1967

For the electrostatic processing of mineral mixtures, especially salt minerals or salt mixtures, it has proven to be advantageous to remove the substance mixture to be separated before the actual separation to be treated with chemical conditioning agents in an electric field and then dried. One only thermal treatment without the addition of conditioning agents also leads to the goal, requires but higher energy consumption, which endangers the economic viability of the process.

Lower preparation and separation temperatures can be achieved with conditioning with chemical agents be applied. Separations at even lower temperatures can be achieved when using partial or air completely freed from water vapor before the actual conditioning and when it is avoided any supply of water or water-like solvents to the material to be processed through conditioning can be achieved with aqueous or water-like solutions. This dehumidification requires a considerable technical effort for the preparation of mineral mixtures, whereby the The economy of the process is also deteriorated.

The conditioning agents used are, for example, anionic substances, i. H. such substances that form negatively charged molecular residues by splitting off one or more H or Me ions. Also find sulfonates, acid anhydrides, polyvalent substances with at least 6 carbon atoms and one larger number of functional groups p as well as silicones, dyes application. The conditioning agents are mainly used in dissolved form, especially in aqueous solution, alone or in a mixture.

It has also been proposed that the conditioning agent or a combination of these agents should first be applied to carrier substances with a large surface and, with the aid of these prepared carrier substances, the conditioning agent should be transferred to the mineral mixture to be treated. Inorganic and organic substances with a large surface area, such as kieselguhr, talc, synthetic silicas, silicates, metal oxides, activated carbon, starch, are suitable as carrier substances. The carrier substances alone have no influence on the separability of the mineral mixtures. In order to be able to work at relatively low temperatures, the conditioning agent must be applied without a solvent. Furthermore, in order to achieve optimal separation effects, it is necessary to work with air that has been partially or completely freed from water vapor. In all cases, this type of conditioning requires a large amount of carrier material. Process for electrostatic processing
of mineral mixtures, in particular
Salt minerals or salt mixtures

Applicant:

Wintershall Aktiengesellschaft, Celle;
^j 5 Kassel, August-Rosterg-Haus

Named as inventor:

20 Dr.-Ing. Arno Singewald, Wathlingen via Celle; Dipl.-Chem. Dr. Günter Fricke,
Röddensen on Lehrte

25th

30th

35

40

45

50 The preparation of the carrier and the dehumidification of the air require considerable technical effort, which can call the economic viability of the process into question.

It has now surprisingly been found that by combined and successive continuous or discontinuous treatment of the mineral mixture with highly dispersed water adsorbents, such as silicas, soda lime and chemical conditioning agents, achieved excellent separating effects will. It is possible through this procedure, the amount of water adsorbents, for example synthetic silica, by about 30 to 80% compared to the amount of carrier substance according to the known Procedure to decrease. The amount of chemical conditioning agent can also vary according to the Processes according to the invention can be reduced by about 25 to 50% compared to the amount according to known ones Procedure. It has also been found that post-conditioning occurs when the preconcentrate is subsequently separated can be omitted entirely. The technical progress of the process according to the invention results from the example below:

709 647/53

Table 1

Items to be reprocessed: hard salt with 15.6 _{% K 2} O and 32.0% kieserite, separation temperature: 70 ° C

attempt No.

Conditioning

Amount, g / t a) silica b) fatty acid

K ₂ O content%

concentration

Residue

K ₁ O shares

concentration

Return

Na salts of fatty acids in 10% aqueous solution

Fatty acid on silica as a carrier

separate addition of silica and fatty acids

a) -

b)

a)

b)

a)

b) 40.2 36.1

46.5

1.7 1.4

1.0

55 48

62

In operating the method according to the invention, the reduction in the water adsorbent and the fatty acid is about one third about a quarter. In other processes, 200 g / t silica and 100 g / t fatty acid required, so that for the claimed process a reduction of about 80% Silica and about 50% fatty acid.

In the procedure according to the invention, the salt mineral, such as crude potassium salt, is preferably used first intensively mixed with the highly dispersed water adsorbent, and then the fatty acid is added.

It is also possible to reverse the order in which the funds are added; H. the goods to be processed first with chemical conditioning agents and only then with highly dispersed water adsorbents to treat. For post-conditioning, however, it is advantageous to first treat the starting product with the Treat water adsorbents.

The necessary mixing time depends on the water adsorbent used and is evident controlled by the rate of water adsorption. This mixing time is generally between 1 minute and 1 hour, preferably between 1 and 5 minutes. The mixing takes place in known devices, such as. B. in a Lödige mixer or in Mixing screws with the cold components.

In table 1, the K ₂ O contents of the preconcentrate and the residue _{are listed in column c and the corresponding K 2} O proportions after a single separation are listed in column d. _{The K 2} O proportions of the average product resulting from the difference to 100% have not been listed for a better overview.

Test 3 according to the method according to the invention shows a pre-concentrate which is 6.3 and 10.4% higher than comparative tests 1 and 2. The K 2 O output is 7 and 14% higher than in tests 1 and _{2, respectively} 2 according to the state of the art. In the method according to the invention, the circulating medium is about 10% smaller than in tests 1 and 2, which expresses the considerable increase in the throughput of material to be processed.

The following examples in Table 2 show the operation of the claimed process with different, highly dispersed water adsorbents (Trials 11 to 18) and with fatty acid as a chemical conditioning agent.

Experiment 5 relates to the addition of only water adsorbents and experiment 6 to the addition of only fatty acids, namely a synthetic fatty acid with C ₆ to C ₉ , predominantly saturated. In contrast, experiments 7 to 10 relate to the addition of substances with a large surface area which have no or only a slight water adsorption effect.

Tabel

^{Material to be processed} : Hard salt with 15.6% K ₂ O and 32.0% Kieserite, separation temperature: 60 ° C

Water adsorbent Conditioning

K ₂ O content Vo

concentration

Residue

K ₂ O shares

concentration

Without water adsorbent and without fatty acid

Commercial product »Siloid 75« (from OMYA) without fatty acid

only fatty acid

Diatomaceous earth + fatty acid MgO + fatty acid Talc + fatty acid Calcium phosphate fatty acid

125 150

330 330 330 330

11.5

20.2 32.4

25.0 31.8 24.5 19.0

13.5

4.0 3.4.

4.0 2.8 5.3 6.8

13th

22 30

29 35 17 14

Table 2 (continued)

attempt No.

Water adsorbent conditioning

Κ, Ο content

concentration

Residue

K ₂ O shares Vo

concentration

Residue

"Siloid 75" (from OMYA) + fatty acid

Silica »KS 300« (Hoesch)

+ Fatty acid

Silica »KS 404« (Hoesch)

+ Fatty acid

Bentonite (v. Heiden) + fatty acid Silica »DS« (Filler GmbH)

-f- fatty acid

Soda lime powder + fatty acid

"Siloid 75" + fatty acid

"Siloid 75" + fatty acid

KC drying pearls (from Kali-Chemie) Siogel grain size 3 to 6 mm (Chem. Fabr. Oker, Braunschweig)

125

125 125

125 330 75 50 800

800

46.5

42.8

43.2 29.7

43.6 33.6 40.0 36.0 30.5

32.7

1.0

1.0

1.0 2.1

1.0 2.1 1.5 2.0 1.5

1.6

62

60

60 45

53 42 56 49 61

61

2 3

3 5 4 4 4

Runs 1 through 20 show in column b the K ₂ O content and column c of the K ₂ O content in the concentrate and residue after a single passage through a well-known free-fall separator. _{The K 2} O shares remaining in the medium, which represent the difference to 100% and which are returned in a continuous, closed process, were not included.

The effect of the combined and sequential addition of water adsorbents and thereafter of fatty acids clearly emerges from the test results. The surprising effect of the Apparently, water adsorbent is essentially based on the fact that the material to be processed is wholly or is partially freed from adhering water films. This is also evident from experiments 7 to 10, which with substances with a large surface area, but with little or no water adsorption property were obtained. These substances of experiments 7 to 10, which give good results according to known methods as carrier substances for conditioning agents, result in the method according to FIG Invention no technically useful separation effects. This finding can be described as surprising.

The highly dispersed water adsorbent can be powdered or granulated Shape can be used. It is also possible to use grained or granulated material to be processed To mix water adsorbent intensively and this before the addition of the chemical conditioning agent z. B. by sieving or sifting to remove.

The separation of the starting materials can take place in a wide temperature range, namely between Room temperature and the decomposition or evaporation temperature of the conditioning agent take place.

For the method according to the invention, it means a considerable technical advance that the Treatment of the material to be reprocessed with air of defined humidity can be entirely or largely dispensed with. It This makes it possible to save the technically complex and expensive air dehumidification. Furthermore, the The large amount of air required for heating and drying the material to be processed can be reduced or omitted entirely. This advantage of the claimed Procedure results from experiments 21 to 28 of the following table.

Tabel Processing material: hard salt with 15.6% K ₂ O and 32.0 ° / ₀ Kieserite Conditioning

Degree of filling of the closed material filled with the ground to be processed Container% K ₈ O content

concentration

Residue

KjO shares ° / o

concentration

Na-salts of the fatty acids in the 10 ° / oig ^e r aqueous solution

Fatty acids on silica as a carrier

combined and successive addition of highly dispersed water adsorbent and chemical Conditioning agents

25 50

50 100

25 50 75 100 21.1 19.5

33.0 34.7

42.0 43.5 39.5 36.2

9.0 12.2

2.1 2.1

1.2 1.1 1.5 1.6

32 30

44 44

60 64 54 51

The results in experiments 21 to 28 were obtained with material to be processed which, after the treatments with the agents, was brought to a separation temperature of about 60 ° C. without the supply of fresh or circulating air. Spalteb shows the K ₂ O content and Spaltec the K ₂ O content in the concentrate and residue after a single separation in the free-fall separator.

Experiments 25 to 28 according to the method according to the invention show surprisingly good separation results without the supply of fresh air or circulating air. These Operation is possible according to the claimed process because the highly disperse water adsorbents used act as water regulators in the phase interface and the chemical conditioning agents become effective as a result can. In contrast, the same highly disperse water adsorbents have poorer properties when used as a carrier substance for the conditioning agent Separation results because the water absorption

is reduced by the applied conditioning agent. As a result, according to the known method, air conditioning is necessary in order to achieve technically useful separation effects. Furthermore, this process requires that no solvents, in particular water, be used. This requirement is not necessary according to the claimed method. The chemical conditioning agent can be added in an aqueous solution without impairing the separating effect. The solvent, in particular water, is adsorbed directly by the highly dispersed water adsorbent and thereby loses its disadvantageous effect on the separation of the material to be processed. According to the process of the invention, in addition to higher concentrates and a better K ₂ O yield, as shown in Table 4, significantly higher K ₂ O contents are also achieved in the individual sieve fractions, as can be seen from Table 5.

Table 4

Items to be reprocessed: Hard salt with 15.6% K ₂ O, separation temperature: 60 ° C

attempt
No. Conditioning Pre-concentrate First
Post concentrate
"/.K _j O K ₈ O yield
% 29 Na salts of fatty acids in 10% aqueous solution 43.0 55.7 91.3 30th Fatty acid on silica as a carrier 37.2 56.7 92.3 31 Combined application according to the procedure according to the invention 45.7 60.5 95.1

Quantities per ton of crude salt

29 Treatment with 275 g fatty acid

30 treatment with 200 g fatty acid applied to 800 g silica, type »KS 300«

31 Treatment with 125 g silica, type »KS 300« and 150 g fatty acid in substance, (C ₅ - C ₉ )

Table 5 Experiment No. 29 (comparative experiment)

Grain range mm

lower, 0

0.75 to 1.0

0.5 to 0.75

0.3 to 0.5

0.2 to 0.3

0.16 to 0.2

0.06 to 0.16

over 0.06

Raw salt

15.6

Pre-concentrate

K ₂ O content, »/ 0 43.0

Kieserite content, "la 8.3

K ₈ O content%

32.0 Grain fraction Grain fraction 7o ° / o 1.3 1.0 10.1 8.6 23.9 24.5 22.8 26.0 12.4 13.9 7.3 7.5 17.4 15.3 4.8 3.2

First post concentrate 55.7 6.1

Grain fraction K ₂ O content % 7o 0.4 44.3 3.4 48.0 13.8 53.6 24.3 56.8 18.6 57.1 12.3 56.1 24.2 55.2 3.0 47.5

33.5 44.1 45.2

35.2

Claims (10)

9 10 Experiment no. 31 (method of operation according to the invention) Rohsak | Pre-concentrate | Post concentrate K2O content, ° / o 15.6 I 45.7 J 60.5 kieserite content, ° / o 32.09.72.4 up to 1.0 10.16.91.256.50.5 up to 0.75 23.920.342.69.259.90.3 up to 0.5 22.825.625.760.70.2 up to 0.3 12.414.851.722.360.70.16 up to 0.2 7.39,514,361, 00.06 to 0.16 17.418.824.660.5 over 0.06 4.83,946,22,758.1 The post-concentrate of experiment no. 31 shows a K2O content that is 4.8% higher than the post-concentrate after comparative experiment no. 27. According to the claimed process, the selectivity in the intergrowths in the post-separation remains significantly greater than according to known processes. The crude potash salt used for the experiments in Tables 1 to 5 is a finely intergrown hard salt which, according to the sieve analysis according to Table 5, has an integral degree of digestion of 69.6%. When processing finely intergrown hard salts, it is not possible according to known processes to use a two-stage separation process to achieve final concentrates with a K2O content of at least 58% K2O as. On the other hand, a final concentrate with over 60% K2O can be achieved in two stages using the claimed process. This result is of considerable technical importance for the preparation of mineral mixtures, in particular salt minerals or amounts of salt. Further tests relating to sylvinite (test numbers 32 and 33) and fluorspar (numbers 34 and 35) and stinkspar (number 36) are disclosed in Table 6 below. Table for processing: sylvinite with 17.2% K2O separation temperature: 50 ° C test number conditioningg / t pre-concentrate post-concentrate K1O yield32 »Syloid 75« (OMYA) + fatty acid ... 12547,361,994,017033KC-Trockenperlen (Kalichemie) 50047, 962.195.3+ fatty acid200 separation temperature: 70 ° C test no. Conditioning materialg / tfirst concentrate percentage of usable mineral yield% 34 fluorspar »Syloid 75« 12587.593.157.3% CaF2 + fatty acid20035, fluorspar «syloid 75« 12598.98.98.491.6% »Syloid 75« 12598.98.988.491.6% »Syloid 75« 12598.98.988.491.6% 295.193.6% CaF2 + fatty acid200 claims: 1. Process for the electrostatic processing of mineral mixtures, in particular salt minerals or salt mixtures in known separators, in particular free-fall separators with chemical conditioning agents, characterized in that after the combined and successive, continuous or discontinuous treatment of the mineral mixture with highly disperse water adsorbents in powdery or granular or granular form, such as Silicas, soda lime, by intensive mixing 709 647/53 in about 1 minute to about 1 hour, preferably in 1 to 5 minutes, and with chemical conditioning agents, optionally vice versa Order in which the separation is carried out in one or more stages. 2. The method according to claim 1, characterized in that the separation at temperatures takes place, which takes place between room temperature and the decomposition or evaporation temperature, in particular at 60 ° C. 3. The method according to claims 1 and 2, characterized in that the treatment of the Items to be reprocessed with air of defined humidity are completely or partially omitted. 4. Process according to claims 1 to 4, characterized in that the heating and The amount of air required for drying the material to be processed is reduced or omitted. 5. Process according to claims 1 to 4, characterized in that the highly disperse water ao adsorbent is separated prior to the addition of the chemical conditioning agent. 6. The method according to claims 1 to 5, characterized in that the chemical conditioning agent is used in aqueous solution or in water-like solvents. 7. The method according to claims 1 to 6, characterized in that the post-separation without Post-conditioning takes place. 8. The method according to claims 1 to 7, characterized in that the starting product first with the post-conditioning Water adsorbent is treated. 9. The method according to claims 1 to 8, characterized in that the medium is returned to the input material. 10. The method according to claims 1 to 9, characterized in that a concentrate with at least 60 ° / o K ₂ O is produced from kieseritic potash crude salt in two separation stages. 709 647/53 9.67 O Bundesdruckerei Berlin