The ancient practice of alchemy sought to turn base metals into gold, but it also laid the foundations of modern inorganic chemistry.

So the work of PhosphonicS, using inorganic substances to recover gold and other precious metals such as rhodium and platinum from effluent, could be described as almost alchemy.

Industrial processes often use considerable quantities of precious metals, particularly as catalysts.

Where the waste or tailings are in solid form, there are well-established methods of extracting the metals for re-use. But if part of the waste is in liquid or slurry form, recovery is far more difficult.

Concentrations of the metals may be very low, but if the effluent amounts to hundreds or thousands of tonnes per annum, the value of metal lost is considerable and an efficient method of recovery economically viable.

Otherwise, the waste will be allowed to solidify and probably burnt.

At its Milton Park laboratories, PhosphonicS has developed and continues to research its Cleantech technology for metals recovery.

Chief executive Dr David Astles explained: “Organic materials are carbon, inorganic are non-carbon. We take the appropriate silica, the non-organic, and attach organic chemical groups to the silica’s surface. We call these groups the grabbers.

“Then, just like your filter jug at home, we pass the effluent through the modified silica and the metal we want to recover attaches to the silica’s surface. That gives a solid compound that is passed to one of the metal specialists like Johnson Matthey. They then employ their standard techniques to extract the metal from the silica.”

The beauty of the process is that it recovers only the target metal, it is highly efficient and works at negligible concentrations.

Dr Astles said: “Recovery is 90-95 per cent efficient, any other metals are ignored and we work on concentrations as low as 1-20 parts per million.”

Eager customers are the petrochemical industry, prime users of catalysts and electronics, where precious metals figure strongly in chip and wafer production.

Silica is probably best known as a component of sand and sandstone, but that one word covers a multitude of varieties.

A glance at the PhosphonicS’ silica library shows row upon row of apparently identical substances, but distinguished only by their labels.

Choosing the appropriate silica for a process is a key component of success.

The company is the brainchild of Professor Alice Sullivan, a known authority on silica and making specialist materials from it.

PhosphonicS was spun out in 2003 at Prof Sullivan’s labs in Queen Mary College, London. In 2005, the company received its first funding and relocated to Milton Park, giving it bigger premises, room to expand and access to the Oxfordshire cluster of highly trained and experienced staff.

Dr Astles was appointed chief executive to coincide with the move. Dr John Wilson, Prof Sullivan’s husband, is chief technology officer.

The company name stems from the green catalysts the company has developed by attaching phosphonic acids to silicas. Phosphonic acids are near relations to phosphoric acids.

Significant revenues are generated by using the recovery technology to purify pharmaceutical compounds prior to clinical trials.

“These compounds invariably contain metals and organics,” Dr Astles said.

“The impurities can and do affect the action of the compounds in the trials, so it’s critical to purify them to ensure accurate results.”

The company has just gained second-round funding of £3.5m to expand its staff complement and further research its technologies. It is a measure of the difficulties of finding venture capital that this tranche came from Seventure, a Paris VC house that invests in life sciences.

At present, PhosphonicS employs 17 staff, a mix of organic, inorganic and analytical chemists. The last of these are vital in researching accurate methods of measuring metal concentrations in wastes and the quantities extracted.

Two business development managers, one in precious metal recovery and one in the pharma sector, are taking the products into the market place.

By the end of the year, five more staff will have been recruited and the short-term objective is to grow the team.

Longer term, the profits from existing business will be used to develop green, recyclable catalysts — those in current use often produce toxic waste.

As for many SMEs, marketing the name and the products is not easy. PhosphonicS uses the Internet, e-mail and contacts made at conferences and meetings to build and maintain its customer base.

By keeping these contacts regularly updated, the company retains their interest.

As the company grows and diversifies, it will be examining end-to-end processes and the role it can play within the recycling industry. As we strive for purer drinking water, removing traces of arsenic could be one application.

Dr Astles said: “We’re extracting very high values from waste and there’s not many companies that can make that claim.”

Name: PhosphonicS Ltd Established: 2003 Chief executive: Dr David Astles Number of staff: 17 Annual turnover: Confidential

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