Oxygen Cleaning

What Is Oxygen Cleaning?

Contaminants within a system that uses oxygen can pose serious risks. If dirty industrial equipment is used in an oxygen rich environment, fire, or explosion, could result. When equipment is used for medical purposes, oxygen cleaning removes contaminants that can cause physical harm.

Fire

There are three things that fire needs. One of them is oxygen. Where there is oxygen, a source of heat and a fuel, there can be a fire or even an explosion.

Many industries use oxygen – mining, healthcare, chemical processing. Equipment needs to be free of contaminants as these could serve as a fuel. Various processes can then create a heat source which could lead to fire.

Potential heat sources are:

  • Friction from metals or other materials sliding against each other
  • Static electricity
  • Impact
  • Resonance or vibration
  • Compression of a liquid

Autoignition

Autoignition occurs when a fuel source spontaneously ignites due to the introduction of heat. Heat can be produced by a sudden compression of gas (or liquid). If this occurs in an oxygen rich environment, it will cause an explosion.

Contaminants

What contaminants need to be removed? Anything that can cause combustion or autoignition. There are 3 types of contaminants:

Organic

  • Volatile Organic Compounds – These compounds have a high vapour pressure and low water solubility.
  • Greases / Oils – Hydrocarbon based oils and grease

Inorganic

  • Nitrates – nitrogen-based compounds
  • Phosphates – often used in combination with other elements
  • Detergents (water-based) and cutting oils (coolant, lubricants)
  • Solvents / Acids

Particulate

  • Lint and fibres
  • Dust
  • Welding slag – this is vitreous material that is produced as a byproduct during some welding processes

Stay safe in your industrial working environment by being scrupulous in your cleaning methods.

The Most Common Gas Types

What are the most common gas types?

Argon

Argon makes up approximately 1% of the Earth’s atmosphere. It is the third noble gas. Argon is chemically inert and is colourless and odourless in both its liquid and gas forms. Argon is used when an inert atmosphere is required. This is needed in the production of some reactive elements including titanium. Argon is used by welders to protect the area of welding. It is also used in incandescent light bulbs.

Oxygen

Oxygen is colourless, tasteless and odourless. It is a gas and is vital to all living organisms. Animals take up oxygen and convert it to carbon dioxide. Plants use this carbon dioxide and then produce oxygen which is returned to the atmosphere.

21% of our atmosphere is made up of oxygen.

Helium

Helium is an inert gas. It is the second lightest element and has no colour, smell or taste. Helium becomes liquid at −268.9 °C. In order for helium to become a solid pressure of 25 atmospheres is required as well as a temperature of -272 °C.

Helium is used for welding various metals, to pressurize fuel tanks for rocket propulsion.  It is used as a lifting gas for balloons carrying meteorological equipment.

 

Hydrogen

This is the lightest element. Hydrogen is a gas – colourless, odourless, tasteless and very combustible. It is non-toxic. Hydrogen makes up approximately 75% of all matter in the universe.

Hydrogen is used to make ammonia for fertilisers as well as cyclohexane and methanol used in the production of plastics and pharmaceutical products.

Nitrogen

Nitrogen is a gas that has no taste, smell or colour.  It is a gas that is found in all living matter. Nitrogen is the most common element in the earth’s atmosphere.

Nitrogen is used in fertilisers, dyes, explosives, nylon, and nitric acid.  Nitrogen needs to be reacted with hydrogen in order to produce ammonia.

If people are exposed to high concentrations of nitrogen, it is harmful to health.

Because it displaces oxygen in an enclosed space, it can build up to dangerous levels.

Approximately 78% of our atmosphere is made up of nitrogen. Nitrogen is essential for all life.

Acetylene

Acetylene is a hydrocarbon and is the simplest alkyne. It is a colourless gas with a pleasant odour.

Acetylene is used as a fuel and a chemical building block. It is commonly handled as a solution due to the fact that in its pure form it is unstable.

One major use of acetylene is in the fabrication industry.  It is used for welding, cutting, brazing, hardening and texturing.

Acetylene is inflammable but it has the potential to explode in both liquid and solid form when under pressure of approximately 15 pounds per square inch.

Carbon Dioxide

Carbon dioxide is very important as part of the earth’s air. It is non-flammable and colourless.  At normal pressure and temperature, it is a gas.

Carbon dioxide is used in fire extinguishers and for inflating life rafts and jackets.  It is used as a refrigerant and for blasting coal.  It is helpful in promoting plant growth in greenhouses.

Air

The atmosphere of earth is known as air. It is the layer of gases that surround the planet.  The atmosphere protects life on earth – it creates pressure which allows for liquid water to exist on the surface of the earth. It absorbs ultraviolet radiation from the sun and allows the earth surface to be warm.  It also reduces the temperature extremes of day and night. Air is mainly made up of nitrogen and oxygen.

Oxygen in Gold Mining

Why is oxygen needed in gold mining? Mines use oxygen in a process called cyanide leaching. This process is used to extract gold from the ore. It uses pressure oxidation and cyanidation. Using oxygen increases recovery of gold and reduces the costs created by cyanide as well as reducing waste.

Increasing Gold Recovery
Using more dissolved oxygen in slurry intensifies the cyanidation process. Recovery rates can be expected to increase by a full percentage (at least) when the levels of dissolved oxygen are increased.

Improved Silver Recovery
As with gold recovery, so too can silver recovery be improved by increasing the levels of dissolved oxygen in the ore bearing slurry.

Lower Cyanide Costs
The process of cyanidation is dependent on the reaction of gold, cyanide, water and oxygen in the mined slurry. More dissolved oxygen means less cyanide needed in this process and thus cyanide costs are reduced significantly.

Lower Waste Treatment Costs
Some of the generated oxygen can be used as an oxidizing agent in the treatment of mining wastewater. It can be passed through an ozone generator and then injected straight into the wastewater stream. Also, by decreasing the use of cyanide, there is less to remove from the wastewater.

Foxolution
“Our Oxygen Generating Systems can be customized and tailored for your mining application. Skid-mounted or even fully containerized systems have been designed & developed for easy transportation, placement and maintenance on-site. Using a process of Pressure Swing Adsorption (PSA), to separate oxygen directly from the air, our oxygen generators are the ideal “on-site” solution to the mining industries needs and requirements.” www.foxolution.co.za