DD212256A1 - PROCESS FOR PRODUCING HEAVY METAL BINDING ADSORBENTS - Google Patents

Abstract

The invention relates to a process for the preparation of substituted thiourea-containing absorbents, which are particularly suitable for the absorption of mercury, silver and other metal ions. These absorbents are prepared by reaction v. primary and / or secondary crosslinked aromatic polymeric amines on d. Base of crosslinked gelatinous or macroporous aromatic polyvinyl compounds with amine groups bonded directly or via hydrocarbon bridges to the aromatic nucleus with the reaction product of a thiocyanate and an organic acid halide and / or an aliphatic halocarboxylic acid ester.

Description

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УЕВ СНБЯШЕОМЗІІШ 3ITTEHPSLD Bitterfeld, 2. 12. 1932

2312

Process for the preparation of heavy metals binding adsorbents

Field of application of the invention

The invention relates to a process for the preparation of adsorbents containing substituted thiourea groups on the 3-asi3 of primary and / or secondary amines of crosslinked gelatinous or macroporous vinylaromatic polymers. These adsorbents are particularly well suited to adsorb various jet ions such as mercury ions and noble metal ions.

Characteristic of the known technical solutions

It is known to produce similar condensation-based adsorbents. For this purpose, thiourea, thiosemicarbazide and thiocarbazide are condensed with aldehydes (DE-CS 2128 802). However, such Sondensationsprodukte have a 'sufficient thermal stability and a low adsorption rate to metal ions. To improve these products, thioureas and aldehydes are cocondensed with substances that are mechanically stable

1 σ.MRZ. 1? D3-υ iijiJJ

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and give a suitable three-dimensional structure. Examples of such substances include phenol compounds and aromatic amines (DE-OS 212S 802). The fundamental problems and difficulties in the synthesis and application of Kondensaxionsprodukten could not be legalized thereby.

In DE-OS 2312 233 intact vinyl aromatic structures, such as polystyrene resins are described which contain thiourea groups in addition to amino groups Their use for the removal of heavy metals from solutions is also described, but the adsorption capacity of these adsorbents in the strongly acidic pH range is not satisfactory. and undesirably large amounts of scirrhic metal ions remain in the solutions. These disadvantages are overcome when using crosslinked vinyl aromatic polymers of the styrene-divinylbenzene type of specific porosity (DD-PS 112 277, DE-OS 2314 756, DE-OS 2364 ЗбѲ, DE-AS 2429 944) is a prerequisite that these polymers carry primary and / or secondary amino groups, which are then reacted with thiocyanic acid, salts of thiocyanic acid, optionally substituted thioureas or a mustard oil in the presence of a suspending agent to thiourea group-containing polymers. Adsorbents of the same or similar structure are described in SU-PS 523 113. Chloromethyl-containing styrene-divinylbenzene copolymers or copolymers of г-Спіогте ^ уі ^ -Ѵіпуірут ^ іп be reacted with aromatic amines or diamines and then reacted in an acidic medium with Ajsmoniumrhodanid to the thiourea group-containing polymers. Aliphatic basic structures (polyvinyl chloride polymers) with thiourea groups are described in DE-OS 2326 366 and 2312 2 33.

Object of the invention

The object of the invention was to produce thiourea-containing adsorbents based on vinylaromatic polymers having improved properties.

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Particular importance should be attached to a better compatibility of the adsorbents, especially for the metals mercury and silver.

Explanation of the essence of the invention

The object of the invention was to provide a favorable process for the preparation of adsorbents with substituted thiourea groups.

Surprisingly, it has now been found that it is possible to prepare substituted thiourea-containing adsorbents based on crosslinked gelatinous and / or macroporous vinylaromatic polymers in a one-pot process, if лап primary and / or secondary amines containing vinylaromatic polymers with the reaction product of a thiocyanate and an organic Acid halide and / or an aliphatic Halogencarbonsäurees he reacted.

The processes of syntheses of crosslinked vinylaromatic polymers having primary and secondary amino groups which are used in the process according to the invention are known. Likewise, the partial stages of polymerization and the methods for introducing primary and / or secondary amino groups, such as ilitrierung and reduction, chloromethylation and amination or amidomethylation and subsequent saponification.

The spatially crosslinked copolymers which come to the process according to the invention are products obtained by bead polymerisation of a mixture of one or more monovinyl compounds, one or more polyvinyl compounds, with or without addition of small amounts of one or more polymerizable compounds polar vinyl compounds and are prepared with or without the addition of inert substances. Examples of suitable Llonovinyl compounds are:

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Styrene, Substituted Styrenes and Vinylnaphthalene The number of polyvinyl compounds which can be used as ethers is very extensive. Examples of preferred compounds which may be mentioned are: divinylbenaols and trivinylbenzenes. Primarily crosslinked polystyrenes of industrial significance have been obtained. 3. from the system styrene and divinylbenzene optionally with the addition of small amounts of acrylonitrile or other polar monomers and / or falling or swelling inert substances, such as. Б. aliphatic or aromatic hydrocarbons are obtained. The amount of polyvinyl compound used as crosslinker can be varied within wide limits. Preferably 1 to 20 weight percent of the polymerizable phase is added. The compounds referred to as additives above are preferably used in 1 to 15 weight percent, based on Gesamtaonomerenmenge. The addition of inert substances can be varied within wide limits and can lead to intermediates to truly sacroporous products.

If the above-described polymers do not already contain primary and / or secondary amino groups through the use of corresponding vinyllaborates, they are introduced into the polymers in known manner according to the processes cited above.

The process according to the invention also condensation resins can be used. Their syntheses are also known. They are obtained in general by condensation of aliphatic or aromatic amines ad., Polyaldehydes or z-chlorohydrin, Examples of aliphatic amines are polyalkylenepolyamines and aromatic amines are phenyldiamine However, surprisingly, they can be converted into high levels of adsorbents with acyl-substituted and / or carboxylic acid-substituted thiourea groups

о., Щ 1933-

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primary and / or secondary amino-containing polymers with acyl thiocyanates are reacted by stirring and heating in a solvent. As acyl isothiocyanates are isothiocyanates with aliphatic acid radical, such as. 3. the Acexylgruppe, the propionyl group as well as aromatic Saureres ze such. 3. the benzoyl groups used. These intermediates can be easily, z. 3. produce by reaction of 3enzoylchlorid, with potassium thiocyanate, love this 3eispiel can be used other acid chlorides and other inorganic and organic thiocyanates.

The advantage of the method according to the invention is a 3-pot reaction. For example, potassium thiocyanate is dissolved in acetone for this purpose; and 3enzoylchlorii added and the reaction carried out at 30 C. The amino-containing polymer is then added to the reaction solution without isolation of the intermediate, and the reaction is carried out at 50-60 G. The by-products of the first reaction stage do not interfere with this. "" Elaborate isolation work of the acyl isothiocyanates thus omitted. As solvents or suspension agents such liquids or liquid mixtures are contemplated, which are inert under the Reaktionsbedingun g s relative to the Reaktionsxeilnehmern, such as aromatics, ethers and ketones. Preference is given to using those solvents which on the one hand are swelling agents for the polymers carrying amino groups and, on the other hand, solvents for the starting materials and intermediates. Examples of preferred solvents for the reactions are acetic and cyclohexanone. Temperature and time can be varied over a wide range for both partial steps. in the

In general, temperatures of 20 G to the system reflux temperature and reaction times of 2 to 2 p hours are sufficient. Зеііе parameters are in the daily of the Ar ¹ ; and the structure of the employed primary and / or secondary amino-bearing polymers. Following the same reaction procedure and reaction conditions, halocarboxylic acid esters can be reacted with thiocyanates to give corresponding intermediate products, and these in turn with the polymers containing amino groups.

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Preferred halogenated carboxylic acid esters include, for example, methyl chloroformate and ethyl chloroacetate.

The inventively prepared substituted thiourea-containing polymers have a high adsorption capacity for metals such as mercury, silver and gold compounds. In addition, they are suitable for the adsorption of other metal ions, such as those of platinum metals and zinc.

The adsorbents produced according to the invention are distinguished by a high and selective adsorption capacity for mercury, even in strongly acidic solutions; also by their high adsorption speed. The adsorbents according to the invention also have the door part that they can be produced in terms of application-favorable parameters.

embodiments example 1

In a sulfonating flask equipped with a thermometer, reflux condenser and stirrer, 1.2 mmol of KSCH are dissolved in 600 ml of acetone, then 1 mol of benzoyl chloride are added dropwise and stirred for 2 hours at room temperature. Thereafter, 112 g of a закго-porous anion exchanger with Jdonomethylamiiiggruppenungen in Aminfona set and stirred for 10 hours at reflux temperature. After cooling, the resin is separated from the reaction medium and washed with water.

The analysis of the product gives the following characteristics: total basic weight capacity: 1 ^ 56 meq / g total weight capacity mercury: 5.17 meq / g total weight capacity silver: 1.4-4 meq / g

Blement analysis: 3.29 % sulfur

5.57 * nitrogen

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Example 2

In a sulphonation flask of the same equipment as in Example 1, 1.2 nol of KSCT are again dissolved in 600 g of acetone and 1 mol of ЗепгоуісЫо-rid added dropwise and stirred at room temperature for 2 hours. Thereafter, 135 g of a macroporous anion exchanger with Äthylendiamingruppierungen be entered in the Arainfonn and stirred for 8 hours at reflux temperature. After cooling, the resin is separated and washed with acetone and then with ϊ / asser.

The final product analysis gives the following characteristics: total basic weight capacity: 1.50 meq / g total mercury capacity mercury: 6.07 meq / g total weight capacity silver: 3.21 meq / g total weight capacity copper: 2.70 meq / g

Slementaranaljse:. 6.62 % sulfur

8.07 % nitrogen

Example 3

Following the same principle as Examples 1 and 2, Example 3 is also carried out. Su the intermediate benzoylisothiocyanate, prepared from 1.2 moles of KSCH and 1.2 moles of benzoyl chloride in 600 ml of acetone at 50 ° C and 8 hours reaction time ,, are added in the same reaction solution, 135 g of a macroporous weakly basic anion exchanger with primary Aminogruppierungeri in the amine form and stirred at 55 C for 15 hours. The resin is separated from the reaction solution and washed with acetone, methanol and water.

The analysis of the final product gives the following characteristics: total basic weight capacity: 1y75 meq / g total weight capacity mercury: 5.97 meq / g total weight capacity silver: 2.03 meq / g

Slementar analysis: ^Д , ^Д 3> sulfur

6.36 % nitrogen

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BeisOjel 4

In a sulphonation flask of the same equipment as in Examples 1 and 2, 0.6 mol of KSCH are dissolved in 400 ml of acetone and 0.5 mol of acetyl chloride added dropwise and then stirred for 2 hours at room temperature in this mixture of reaction product, by-products and solvents 45 g of a macroporous anion exchanger with monomethyl groups in the free Aoinforsi registered and stirred for 10 hours at reflux temperature. Subject to cooling, the resin is separated and nachge-wash with water.

The analysis of the product gives the following characteristics: total basic weight capacity: 2.64 meq / g total weight capacity mercury: 5 »54 nrval / g total weight capacity copper: 2.46 meq / g

Slementar analysis: 3 »55 % sulfur

4.60 % nitrogen

el 5

In a sulphonation flask of the same type as in the preceding examples, 1 mol of KSCH are dissolved in 350 ml of acetone and 1 mol of methyl chloroformate is subjected to sodium hydroxide, and the reaction is carried out at 4 ° C. for 4 hours and at 50 ° C. for 2 hours. In the reaction mixture, 100 g of a weakly basic anion exchanger with primary amino groups are added in the amine form and stirred at 50 C for 10 hours, then; clay and water washed.

Stirred at 50 C, then separated and successively ait Ace-

The analysis of the product gives the following characteristics: total basic weight capacity: 1 »42 meq / g total weight capacity: 4.23 meq / g total mercury capacity: 6,17 meq / g total weight-capacity-copper: 2,66 aval / G

Slime analysis: 3.61 % sulfur

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Example б

On the same principle as in Example 5, 1 nol KSCN are reacted with 1 nol of ethyl chloroacetate and the reaction is carried out for 8 hours Ъеі 50 C. Into the contained reaction mixture, 110 g of the weakly basic anion exchanger having primary amino groups are introduced and reacted at 55 C within 15 hours, after separation is washed with acetone and subsequently with water.

The product provides the following analytical methods:

basic Gesanitge-weight capacity; Total Weight Capacity ЗіГЬег: Total Weight Capacity Copper: Total Visible Capacity Mercury:

Elemental analysis:

1.23 meq / g 0.60 meq / g 0.56 meq / g 4.43 meq / g

5.36 fo sulfur 8.82 % nitrogen:

Claims (1)

Claim for merit ^ ^ ^ 2 1 ^ ζ! 5 0 Process for the preparation of heavy metal-binding adsorbents with substituted thiourea groups, characterized in that primary and / or secondary cross-linked aromatic polymeric amines based on cross-linked gelatinous or macroporous aromatic polyvinyl compounds have amine groups bonded directly or via hydrocarbon bridges to the aromatic nucleus with the reaction product be reacted from a thiocyanate and an organic acid halide and / or an aliphatic halocarboxylic acid ester.