What is bioleaching used for?

What is bioleaching used for?

The bioleaching of minerals is a simple and effective technology for the processing of sulfide ores and is used on a technical scale mainly for the recovery of copper and uranium.

What happens to the bacteria after bioleaching?

Bioleaching. Certain bacteria can break down low-grade ores to produce an acidic solution containing copper ions. The solution is called a leachate and the process is called bioleaching .

Where does bioleaching happen?

Bioleaching. Certain bacteria found in the spoil heaps of old mines, can oxidise metal sulfide ores. These bacteria work best in acidic conditions so the spoil heaps are sprayed with acid. Copper(II) sulfate solution is produced and is carefully collected.

Which factors affect bioleaching?

The most common physicochemical parameters that affect the bioleaching are temperature characteristic (mesophilic, moderately thermophilic, or extremely thermophilic), pH, oxygen and carbon dioxide content, nutrient availability, surface tension, and ferric oxide concentration.

What are the main stages of bioleaching?

Phytoextraction

• plants are grown on an ore that contains lower amounts of metal.
• the plants absorb metal ions through their roots and concentrate these ions in their cells.
• the plants are harvested and burnt.
• the ash left behind contains a higher concentration of the metal than the original ore.

What are the disadvantages of biomining?

There are many limitations to these processes, however. A few are the increased cost of mining and processing larger volumes of ore, the limited availability of freshwater needed to mine and process minerals, and the environmental impacts of increased land disruption, waste material, and pollution.

Which bacteria is considered for biological leaching?

Bioleaching can involve numerous ferrous iron and sulfur oxidizing bacteria, including Acidithiobacillus ferrooxidans (formerly known as Thiobacillus ferrooxidans) and Acidithiobacillus thiooxidans (formerly known as Thiobacillus thiooxidans). As a general principle, Fe3+ ions are used to oxidize the ore.

How much does bioleaching cost?

Generally, the capital cost of a bioleaching operation is approximately 50 percent less than that of conventional smelting operation. This is mainly due to lack of infrastructural costs. The operating costs based on current technology for leaching dumps and ores are between 0.18 USD and 0.22 USD per pound of copper.

What metals can be extracted by bioleaching?

Metals extracted from bioleaching include:

• Gold.
• Copper.
• Silver.
• Cobalt.
• Uranium.
• Zinc.
• Nickel.

What is the difference between biomining and bioleaching?

The key difference between biomining and bioleaching is that biomining is the technique of using prokaryotes or fungi to extract metals from minerals whereas bioleaching is the technique of using bacteria to extract metals from minerals.

What do you need to know about bioleaching?

Bioleaching Definition & Process What is bioleaching or biomining? Bioleaching (or biomining) is a process in mining and biohydrometallurgy (natural processes of interactions between microbes and minerals) that extracts valuable metals from a low-grade ore with the help of microorganisms such as bacteria or archaea.

How are microbes involved in indirect bioleaching process?

In indirect bioleaching, microorganisms are not in direct contact with minerals during the process. However, leaching agents are created by microbes, which still oxidise the ore.

Which is an example of a copper bioleaching process?

Copper Leaching: To have an idea of bioleaching process copper leaching by bacteria is described as an example. Covellite, chalcocite and chalcopyrite are generally used as copper ores for bioleaching processes. Apart from containing copper, the ores also contain other elements like iron, zinc and sulphur.

How are metals extracted in a bioleaching process?

Methods described below are generally employed in large scale bioleaching processes: In this method finely powdered ore, approximately 10,000 tons are made into large piles along the slopes of a mountain, and water containing Thiobacillus is continuously sprinkled. Metals are extracted from the water that collects at the bottom of the mountain.