Challenge Summary
In the DSC Zinc plant a manual rotating launder is used to discharge jarosite slurry into bays (4 Nos.). This launder operates in a highly unsafe site operating condition. A safe automated system is required to upgrade the launder (35 m3/hr) with automatic discharge of jarosite slurry into respective bays.
Challenge Scenario
Jarosite slurry treatment is done with lime and cement in the Jarofix plant. This treatment happens in 2 stages present above the launder. Four retention bays at pH 10+ are used for fixation in this plant. The material flow between the bays is managed by a rotating launder that is manually operated with wire ropes by an operator. Jarofix operators fix wire rope in the loader bucket, and the launder supports the rotation from one bay to another. The bay rotation frequency is usually once every four hours, depending on the filling level of the bays.
Currently an operator uses payloader & wire rope to manually control the rotation of the launder. The current manual operation for changeover of discharge bays is dangerous and unsafe, therefore posing risk of accidents to the workforce. Due to manual operation, there is a spillage in the area and production loss. The spillage further leads to jamming the rollers responsible for rotation of the launder. An automated system is required to discharge the jarosite slurry flow from the rotating launder to reduce risks and increase efficiency of discharge.
The technical specification are as follows:
- Launder capacity: 35 m3/ hr of jarosite slurry.
- Jarosite Slurry composition & properties:
W/Zn |
0.20% |
T/Zn |
2.7% |
Pb |
2.5-3.0 % |
Fe |
25% |
pH |
>10.5 |
- Volume of each bay (4 nos): L x H x B : 8*4*10 = 320 m3 each
- Launder height: 3 Meters
- Filled Height for bay discharge changeover: 2 Meters
- Approx. time between changeover: 4 hrs
- Life of launder: in use since 2010