| Nickel recovery from used catalysts | Japan | Before 1994 | Full scale |
MANUFACTURE OF CHEMICALS AND CHEMICAL PRODUCTS # 25
Background
Raney nickel (nickel aluminum alloy) is one of the most popular reduction catalysts in the chemical industry. Disposal of the used catalyst is problematic, which is categorized as hazadous industrial waste.
Nikko Fine Products Co Ltd was founded in 1966. It manufactures metals, metal oxides, inorganic chemicals, food additives, fats, and natural wax, and is also involved in the recovery and regeneration of catalysts.
Cleaner Production Principle
Process modification; Recovery, reuse and recycle
Cleaner Production Application
In the dry method of production, nickel is recovered from the used catalyst after it has been deactivated. Deactivation involves adding to the used catalyst a 15 per cent sodium nitrate aqueous solution. The mixture is agitated, heated at 40-50oC, left for more than an hour, and then rinsed with water. Following this, the used catalyst mixture is burned three times:
| First, the mixture is burned at 800oC for 12 hours in a gas shattle kiln, to remove the water and organic matter in the used catalyst. |
| The catalyst is then roughly ground and burned again, at 1000oC. |
| Finally, the catalyst is burned at 1200-1300oC. |
After this, the used catalyst is finely pulverized, and recovered as nickel oxide. It is important that the temperature is monitored during each stage when the catalyst is burned. The temperature is controlled in the furnace by 10 different monitors.
The disposal of the used catalyst is deactivated with sodium nitrate. Nickel from the used catalyst is recovered and recycled.
Environmental and Economic Benefits
The process is safe in operation, as the used catalyst is deactivated. It produces less waste, as it is disposed off in the dry method. Gas emissions are deodorized and made harmless by full burning with a secondary combustion facility. Complete oxidation occurs during a repeated direct oxidation process and pulverization, so the nickel oxide can be used for pigments used in the ceramic industry, colored glass bottles, and material for ferrite. Compared to the production of general nickel oxide, the process is both simple and low-cost.
Yens per kg of pure nickel
| Before | After | |
| Cost | 700 | 600 |
| Value | 650 | 1350 |
| Benefit | -50 | 750 |
Before the process was introduced, the recovered nickel was used in the production of stainless steel. Now, it is reactivated as nickel oxide. Two hundred tons of pure nickel were disposed off in 1994.
Constraints
None reported.
Contacts
Review Status
This case study was originally published in the UNEP IE document "Cleaner Production Worldwide", Volume II. In the process of preparing the document the case study underwent a technical review.
Subsequently the case study has undergone another technical review by Dr Prasad Modak at Environmental Management Centre, Mumbai, India, in September 1998.