ICIS Innovation Awards: Argex

Extracting more value

Argex’s game changing titanium dioxide manufacturing process is more environmentally friendly and cheaper than existing suphate and chloride options

PHOTO CAPTION: There hasn’t been a major change in the way people make TiO2 [titanium dioxide] in over 60 years, says Roy Bonnell, CEO of Canada’s Argex Titanium. Until now TiO2 has been produced using two processes, the sulphate process was developed in 1916 and the chloride process developed in 1951. Both these use high temperatures and pressures and both have their challenges in terms of sourcing acceptable feedstocks and dealing with toxic residues.

The Argex technology will cut the cost of white pigment

The Argex Technology (AT) is based on solvent extraction. It is a patented closed-loop process that is able to produce high purity TiO2 through a single process directly from the ore material. The innovation lies in how known and proven equipment is used in combination with chemistry and metallurgy.

The ilmenite feedstock is first leached in a hydrochloric acid (HCl) solution. Organics are then added to the solution. These selectively attach to different metals and are brought out in an order that maximises the whiteness of the TiO2, which is hydrolysed out last.

Depending on the economics, the HCl can be recycled to give a closed-loop process that minimises the amount of HCl needed.

Contaminants in the ore body can mostly be extracted as pure saleable by-products. This allows the AT process to use ore bodies with a wider range of contaminants that are not suitable for the traditional TiO2 processes. “We’re not left with the same tailings to deal with. We have essentially inert residuals accounting for less that 10% of the feed and every other by-product is saleable,” says Bonnell.

Tailings
He says Argex has also successfully used tailings from other mineral producers, for example tailings from phosphate rock deposits that contain ilmenite which is too fine to use in the other processes. “This increases the economics for the feedstock producers as well,” says Bonnell.

As well as being more environmentally friendly, the higher energy efficiency, low emissions and saleable by-products also make the AT process an economically attractive prospect. The typical cost of producing a tonne of TiO2 is $2,500-3,000 and the AT process reduces that to about $1,000, says Bonnell. “Compared to the price of TiO2 pigment in North America, which is about $3,400/tonne, that’s a pretty respectable margin. It raises a lot of eyebrows in the industry that this is a game changer,” he says.

Ilmenite Deposit
Argex started work on the process in 2010. At the time the company had its own ilmenite deposit in Canada and was looking for a technology to help it harvest the deposit. “At a certain point we realised that the technology we were developing was probably more valuable than the deposit itself,” says Bonnell.

Roy Bonnell, CEO of Argex (centre), discusses developments in the lab

“So we looked at what we thought would create the most shareholder value and decided that was in becoming a producer of TiO2 pigment rather than as a producer of feedstock for the TiO2 industry.”

Bonnell explains that the original idea for the process came from some consultant metallurgists with a background in the copper and uranium industries. A lot of the development was done in-house but with consultant engineers on board. “Our focus was on the whiteness of the TiO2 and making sure we could get the other metals out. Once we’d managed to do that, the focus was on meeting all the specs needed for architectural paint,” he says. Argex has worked with PPG Industries on meeting these specs.

Since 2011, Argex has had a pilot plant at Valleyfield, Quebec, Canada, and is now in the latter stages of securing the financing to build a 50,000 tonne/year facility. Construction is due to start by the end of the year, with start up in Q1 2017. The initial focus will be the architectural paint market, with plastics and cosmetic, food and pharmaceutical applications to follow.

Most of the production from the new plant is already spoken for. German trader Helm signed an agreement with Argex in August for a seven year offtake of 25,000 tonne/year, while the agreement with PPG accounts for the bulk of the rest of the output.

It is important for Argex to make this first plant a success. “Once we have proven the technology on an industrial scale both technically and economically we have a lot of strategic flex. We could build another plant, license the technology or work with existing producers,” says Bonnell.