Hydrometallurgy

The following are Advantages of Hydrometallurgical Processes except?

• Highly efficient production of metals from low-concentrated and hard-to-beconcentrated raw materials.

• Simple processing of raw materials.

• Economic efficiency due to the usage of sorption and extraction technologies, concentration and separation methods.

• Efficient monitoring of environment

Which of the following is not a factors influencing the leaching process

• Temperature

• Material lumpiness

• Intensity of contact of water with the leaching solution

• Pressure

A mash is pumped into simultaneously operating agitation

units and then pumped out into a catch basin after leaching

• Discontinuous leaching

• Continuous leaching

• Agitation Leaching

• Percolation Leaching

A mash flows through a line of agitation units connected one by one.

• Discontinuous leaching

• Continuous leaching

• Agitation Leaching

• Percolation Leaching

Type of bacteria use during leaching that have the ability to oxidize Sulphur and sulphides to sulphuric acid

• Thio- bacteria

• Ferrobacillus

• Thiobacillus ferrooxidans

Type of leaching bacteria that the source of energy is an oxidation reaction of divalent iron.

• Thio- bacteria

• Ferrobacillus

• Thiobacillus ferrooxidans

Selection of leaching agent depends on many factors. Among the most important are except:

• Chemical and physical character of the leached material

• cost of the dissolving agent

• corrosion effects of the water on the apparatus

• selectivity of the dissolving agent regarding the leached material

Selectivity of a leaching agent is influenced by except

• leaching agent concentration

• temperature

• contact time of the leaching agent with the leached material

• possibility of regeneration of the leaching agent

Leaching rate increases with increasing temperature?

• True

• False

Leaching rate decreases with increasing leaching agent concentration

• True

• False