Portable toilets for underground mines flush with little or no water

8th April 2016 By: Donna Slater - Features Deputy Editor and Chief Photographer

Mining-specific toilets and auxiliary products have been developed by portable toilet and sanitation solutions company Sanitech specifically for underground mines.

These include low-profile portable toilets that can be commissioned in sloping areas with a low ground clearance in underground mines, specialised cartridges and trailer-mounted toilets. The toilets are also designed to have low-combustibility properties, thereby making it possible for them to be used in mines with a high ignition risk, such as coal mines.

Sanitech inland and Africa regional director John Banks tells Mining Weekly that the company started investigating the feasibility of developing toilet solutions for underground mines in 2010.

“At the time, many mines were using open-type drum toilet solutions,” he says, adding that these had several health implications and degraded the dignity of users and those having to clean the drums daily.

Any waste that had accumulated inside the drum was visible, and its open characteristics resulted in noxious fumes being easily spread in the vicinity of the toilets, notes Banks. The situation is compounded when such toilets are placed upstream of shafts, as fresh air from the mine’s ventilation system passes the toilets and spreads the fumes further down the mine.

Further, open-type drum toilets enabled ver-min to spread disease if they entered the toilets and moved through the mine or came into contact with food or water supplies.

“We developed a few concepts for mining-specific toilets, which are now patented in South Africa by Sanitech,” he says.

Sanitech’s first underground mining toilets were supplied in 2014.

A key criteria of the solutions is that the toilets have to be easily transportable.

“These mining solutions also have to be affordable and provide increased dignity for users and the service provider who cleans and maintains the toilets,” says Banks.

Prior to Sanitech’s developing and commis-sioning of underground mining toilets, there was a fast turnover of maintenance personnel, owing to the degrading nature of their work, he notes.

Taking this into account, the company devel- oped a cartridge system (used for storing accu-mulated waste) that uses seals to prevent spillage and fumes from escaping. The cartridge facilitates easy installation and replacing of waste-storage units by a person and mitigates any contact, visually and physically, of the waste material inside.

The cartridges are designed to be stackable, thereby facilitating easy storage and transport in and out of mine shafts.

Sanitech’s mining toilets employ the company’s rotating-bowl dry sanitation system, which uses a nanocoating to create a slippery surface in the bowl, thereby allowing for the toilet to be ‘flushed’ without using water, or very little thereof. In most instances, the water used in the handwash basin is redirected into the bowl to act as a lubricant to further reduce any waste sticking to the bowl.

The nanotechnology removes dependability on water to flush toilets. This is highly advantageous for mines, which are sensitive to water use. “Other toilet solutions use a separate clean-water tank to supply water for flushing, but when this water supply is depleted, the toilet essentially becomes redundant, as it cannot be used until water for flushing is restored.”