CS260562B1 - A method for recovering active ingredients from a desirable poly-component carrier catalyst - Google Patents

Abstract

A method for regenerating active components from a deactivated polycomponent carrier catalyst based on molybdenum oxide, nickel, iron and possibly other transition and alkali metals on silica as a carrier for the oxidation of propene to acrolein, consisting in obtaining an ammoniacal molybdenum leachate and a nitrate leachate from ground tablets of the deactivated catalyst by gradual dissolution in dilute nitric acid with a concentration of 10 to 30% by weight at a temperature of 20 to 100 °C, then in a solution of 26% aqueous ammonia with the addition of 30% hydrogen peroxide and finally again in dilute nitric acid, whereby both fractions of the nitrate leachate are combined.

Description

The invention relates to a process for the regeneration of active ingredients from a deactivated poly-component carrier catalyst.

For the industrial production of acrolein by oxidation of propene is used in Czechoslovakia oxidized catalyst on import carrier, whose catalytic active component consists of a polycomponent system of oxygen metal compounds with the following atomic ratio of metals with ^Mo 2.146 ^Bl 0.881 ^Co 0.389 ^Nl 0.549 ^Fe 0.109, 34 ^X N ^^ 2 4,2 4.29 where X _n - are trace metals such as B, Mg, Cu, Sn, Al, Mn, Ca

A common method of preparing this type of catalyst is to prepare aqueous solutions of salts of the individual active components which are mixed together and the resulting suspension or solution is thickened, dried, thermally decomposed when the carrier is added and the mass thus obtained is tableted and calcined. the desired catalytic properties are obtained.

The price of catalysts for the oxidation of propene to acrolein is considerably high due to the high content of deficit metals and the difficult preparation; the production of this type of catalyst has not been realized in Czechoslovakia yet. The raw materials for the production of the catalyst, i.e. the salts of the individual active components, can only be obtained from abroad, and therefore the cost of the raw materials represents a decisive item or the production of the catalyst. The shelf life of this type of catalyst is limited to 3 years. After this time, the catalyst must be discarded and replaced with fresh catalyst. The deactivated catalyst thus constitutes industrial waste.

Regeneration of the active ingredients from this type of catalyst is a highly demanding matter. Regenerations of related types of catalysts that have been described in the literature are very brief, often referring to only one regenerated component, and virtually all balance data is lacking.

It has now been found that from said deactivated polycomponent catalysts based on molybdenum oxide, bismuth, cobalt, nickel, iron and optionally other transition metals and alkali metals on a carrier carrier, the active ingredients can be regenerated such that an ammoniacal leach is obtained from the milled disactivated catalyst tablets. molybdenum and nitrate extract by successive dissolution in dilute nitric acid at a concentration of 10 to 30% by weight. at a temperature of 20 to 100 ° C, then in a solution of 26% aqueous ammonia with the addition of 30% hydrogen peroxide and finally in dilute nitric acid, the two fractions of the nitrate extract combined.

This method is a three-step process and is quite specific. Extracts from the various dissolution stages can be used together to re-prepare the catalysts or treat the above-mentioned extracts in other areas of the national economy (eg Mo-leach in agriculture, in the fertilizer industry, etc.), Bi, Ni, Co and smaller quantities can be isolated Mo in the form of metals).

The dissolution of the catalyst can be carried out at a temperature in the range of 20 to 100 ° C, but preferably at a temperature of 20 to 80 ° C, in which the dissolution takes place at a reasonable rate and does not result in an intense leakage of NH 2 or. to undesirable development of nitrous gases. In the procedure used, only the analytical control of the Mo and Bi content of the filtrates is carried out, the other metals do not show any significant deviations from their initial determination. The following example illustrates an embodiment of the regeneration according to the invention.

Example

To the dissolution boiler equipped with a reflux condenser and an anchor 10.4 l of distilled water (demineralized) are introduced with a propeller stirrer and then 5 kg of finely ground K 200 catalyst (particle size below 0.6 mm) are introduced with stirring at 400 to 500 rpm and mixed for 10 to 15 minutes. At the same time, the boiler heating is opened and the measuring cup is fed into the boiler

5.63 L (7.83 kg) 65% HNO 3 and the batch is heated to 80 ° C. As soon as the mixture started to thicken appreciably (after about 20 minutes), 6.25 L of distilled water was added and the catalyst leached for a total of 1 hour 45 minutes at 80 ° C. Then the mixture is filtered off under suction, the cake is washed

6.25 1 cold demineralised water (ca 25 ° C). The filtrate and wash water are collected in a reservoir and form 1 part of the nitrate extract (ca 22.4 L).

The filter cake of approx. 8.5 kg is transferred to an ammonia dissolution boiler where it is melted in a mixture of 10 l of 26% aqueous ammonia and then added in portions over 5 to 10 minutes

1.25 L of 30% hydrogen peroxide and stirred at 38 ° C for 45 minutes. After this time, the temperature of the mixture in the boiler is raised to ca 50 ° C and the mixture is stirred for 30 minutes. Then the suspension is filtered off and the cake is washed twice with 4.17 L of cold demineralized water. The obtained ammonia extracts are combined to form a so-called Mo-extract (ca 20 l, ie ca 20.21 kg) with the following composition:

Mo 640 g;

-Ni 8 g;

-C0 6 g;

- SAD ₃ 4.9% wt.

The insoluble ammonia leaching residue (ca 5 kg) is transferred back to the boiler where it is stirred in 8.33 l of demineralized water and immediately thereafter 2.71 l (3.77 kg) of 65% nitric acid is added and the mixture is heated to 80 ° C and leached at this temperature for 90 minutes. It is then filtered off under suction and washed with 6.25 L of hot demineralized water (ca 90 ° C). The obtained extract (ca 15.9 l) is combined with 1 part of the nitrate extract to give ca 38.3 l (43 kg) of the nitrate extract of the following composition:

TTT ca 592 g Bi, 126 g Ni, 89.2 g Co, 23.2 g Fe, and ca 199.5 g Mo.

The two extracts obtained (i.e., the Mo-extract and the nitrate extract) are suitable for the preparation of poly-component catalysts.

Claims (1)

OBJECT OF THE INVENTION Process for the regeneration of active ingredients from a deactivated poly-component supported catalyst based on molybdenum oxide, bismuth, cobalt, nickel, iron and optionally other transition metals and alkali metals on silica as a carrier for the oxidation of propene to acrolein. molybdenum leachate and nitrate leach by successive dissolution in dilute nitric acid at a concentration of 10 to 30% by weight. HNO-j at 20 to 100 ° C, then in a solution of 26% aqueous ammonia with the addition of 30% hydrogen peroxide and finally in dilute nitric acid, the two fractions of the nitrate extract combined.