DE2013945A1 - Mo and co recovery from catalyst residues - Google Patents

Abstract

Catalyst residues contg. Mo (typically 4-8%) and Co (typically 2-5%) are heated in a stream of air, air-stream, or O2-contg. combustion gases at not 900 C, pref. 1100 C, whereby Mo is volatilised as MoO3, leaving Co to be recovered from the residue by reduction and extraction with dil. HNO3.

Description

Process for working up Mo-Co-containing catalyst residues The present invention relates to a process for processing Mo-Co-containing catalyst residues, where purest molybdenum trioxide by volatilization and the cobalt content as salt be won.

It is a method of producing pure for the extraction of Molybdenum suitable molybdenum trioxide known, which is characterized in that one a material containing molybdenum in the oxidized hexavalent state at temperatures between 150 and 500 ° C with one consisting essentially of hydrochloric acid Gas treated, the so-called molybdenum oxychlorohydrin at temperatures between 70 and 540 ° C decomposes and the separated molybdenum trioxide is recycled withdraws the excess gas (DAS t 218 422).

This procedure has when applied to those mentioned in the first paragraph Raw material does not have the disadvantage that the product obtained contains chlorine only molybdenum, but also parts of the cobalt and what may be present Iron, lead and nickel volatilize by chlorination and a pure product only through Repetition of the procedure can be obtained.

In addition, molybdenum oxychlorohydrin, in which form the molybdenum distilled over, very easily due to traces of moisture to a sticky blue Mass hydrolyzed, which is why additional equipment precautions are taken en.

The inventive method for working up Mo-Co-containing catalyst residues, where purest molybdenum trioxide by volatilization and the cobalt content as salt obtained, avoids the disadvantages mentioned. It is characterized by that the residues at temperatures of at least 9000C, preferably 11000C, treated with oxygen-containing, chlorine-free gases and the MoO3 leads away with the gas flow and collects. The treatment gases can be air, others Nitrogen-oxygen mixtures, flue gases or preferably air-water vapor mixtures to serve. These flue gases can come from blast furnace or long-distance gas combustion, their sensible heat being used as heating means for the goods to be treated can.

Ui to explain the method according to the invention in more detail, are for the Catalyst residues, which generally contain, among other things, 4 - 8 Mo and 2 - 5% Co, given in the following treatment examples: Example 1: 21.3 g of catalyst residue with 5.48% Mo and 2.55% Co contents were brought to an experimental temperature in the quartz tube of 1100 ° C and heated for 4 h with air (100 l / h), previously at 900C with steam was saturated, treated.

A loss on ignition of 15% was determined after the treatment.

The residue (s 18.1 g) still contained 0.21% Mo and 3.00% Co.

Thus 96.8% of the Mo head run has been volatilized while cobalt quantitatively remained in the residue.

Example 2t In a second example, the influence of the dwell time the following are stated: 20.9 g of catalyst residue with 5.48% Mo and 2.55% Co content were in the quartz tube to a test temperature heated by 11000C and in contrast to example 1 only 1 h with air (100 l / h), which was previously at 90 ° C with Water vapor was saturated, treated.

A loss on ignition of 14.8% was found after the treatment. The residue (- 17.8 g) still contained 0.32 Mo and 3.0, Co.

Thus 95.0% of the Mo head run has been volatilized while cobalt quantitatively remained in the residue.

Example 3t In example 3, the evaporation was carried out with dry air carried out. 21.9 g of catalyst residue with 5.48 Mo and 2.55 X Co contents were heated in the quartz tube to a test temperature of 1100 ° C and 4 h with 200 l / h treated in dry air. A loss on ignition of 14.6 was found after the treatment. The residue (18.7 g) still contained 0.38% Mo and 3.0% Co. This is 94.1% des Mo-forerun volatilized, while cobalt remained quantitatively in the residue.

Example 4t How little oxygen for extensive volatilization of molybdenum oxide is required, will be explained using Example 4.

A breath gas mixture consisting of 3% oxygen was used as the treatment gas and 97X was nitrogen. The gas mixture was mixed with water before use moistened.

21 g of catalyst residue (with 5.48% Mo and 2.55% Co) became 4 h treated at 1100 ° C with this gas mixture at a throughput of 100 l / h.

A loss on ignition of 11% was determined after the treatment.

In the residue (- 18.7 g) were detected: 1.07, Mo and 2.9% Co. Thus 82.6% of the molybdenum flow has been volatilized, while cobalt has been volatilized remained in the residue.

500 g of the residue made low in molybdenum according to the above examples were used to recover the cobalt for 1.5 hours with 60 l / h hydrogen (case A) and treated with 60 l / h carbon monoxide (case B) at about 1000 ° C.

After the reduction, the residue was diluted with nitric acid (1: 4) and 100 g of the material with 3% Co content in 300 cm3 acid approximately Tests leached for 30 minutes at 600C have shown that leaching is not possible is required to grind up the residue.

The leach residue (~ 95 g) still contained 0.2 ° SO Co while in the lye detected around 92% of the cobalt content of the original material became

Claims (1)

Claim 1: Process for working up Mo-Co-containing catalyst residues, where purest molybdenum oxide due to volatilization and / or cobalt content as salt are obtained, characterized in that the residues at temperatures of at least 900 C, preferably 1100 ° C with oxygen-containing, chlorine-free gases treated and the MoO3 formed in the process carries away and collects with the gas stream and from the practically molybdenum-free residue after reduction with hydrogen or Carbon dioxide-containing gases which cobalt dissolves quantitatively with dilute nitric acid and worked up in a known manner. Claim 2: The method according to claim 1, characterized in that man as treatment gases air, other nitrogen-oxygen mixtures, flue gases or preferably air-water vapor mixtures are used, in the case of the flue gases at the same time their sensible heat serves as a heating medium for the goods to be treated.