Cobalt Blue Holdings Ltd (ASX:COB) (OTCMKTS:CBBHF) is developing the Broken Hill Cobalt Project (BHCP) in far west New South Wales as an exciting new advance for ethical investment and a positive environmental and principled supply solution for cobalt, a metal integral to the world’s sustainable future.
The company’s consulting geologist Dr Ian Pringle explains why the BHCP’s anticipated co-production of 300,000 tonnes per year of elemental sulphur could be an invigorating growth catalyst for a spectrum of Australian industries and will form an important complement to the project’s planned annual production of ~4,000 tonnes of battery grade cobalt.
What’s so good about sulphur?
Sulphur, coffee and life
Consumed at a rate of ten million tonnes of beans each year, coffee is one of the most imbibed beverages worldwide. Coffee is not only cherished for its invigorating properties, but also for its agreeable and penetrating aromas and flavors. These qualities are provided by several (mainly volatile) sulphur-containing compounds.
Sulphur has a plethora of biological properties. It is an ingredient in numerous remedies which include; cancer medications, allergy cures, cholesterol reduction, unclogging arteries, menopause medicines, acne ointments and treatments for respiratory tract infections like the common cold.
Sulphur is present in all living tissues and after calcium and phosphorous, it is the third most abundant mineral in the human body.
World’s leading industrial chemical
Sulphur and its hydroxyl compound, sulphuric acid (H2SO4) are the most widely used chemicals globally. In fact 90% of sulphur production goes towards the manufacture of sulphuric acid and 180 million tonnes of sulphuric acid is produced each year. Few manufacturing industries do not employ sulphuric acid somewhere in their process chain and many are dependent on reliable acid supply.
Sulphuric acid is the world's leading industrial chemical by volume. Among other things, it is used to manufacture detergents, cellophane, rayon fiber, rubber, phosphate fertilizers, pesticides, and lithium-sulphur batteries. It is a major ingredient in numerous mineral recovery and metallurgical processes.
Oil and gas production
Sulphur accumulates occur in various salt domes and on some active volcanoes but sulphur is not commercially mined. Instead it is mostly produced as a by-product in the petrochemicals industry.
Sulphur is generated during petroleum refining. Although conventional oil and gas reservoirs are between 1% to 5% sulphur, recent oil and gas exploration has tapped unconventional reservoirs filled with high sulphur hydrocarbons. The oil from tar sands in Alberta, Canada, is about 20% sulphur and some new fields in the Middle East produce oil that contains as much as 40% sulphur.
Removal of almost all sulphur from hydrocarbon sources is a prerequisite for lower levels of air pollution by internal combustion engines. Acid rainfall, an environmental scourge, is commonly caused by burning fossil fuels containing sulphur gases and nitrogen oxides which combine with atmospheric water to form acids.
As electric vehicles supersede internal combustion motors and coal burning electricity production is replaced by renewable energy projects, less hydrocarbons will be processed and sulphur stocks will diminish.
Australian sulphur and acid imports
Australia’s annual consumption of sulphuric acid is estimated to be over five million tonnes. Imported sulphuric acid is mostly from South Korea where it is produced as a byproduct of metal refining. Sulphuric acid imports to Australia in 2019 were US$13.8m up 39% on 2018.
More than one million tonnes of elemental sulphur is imported each year and this is used mostly for fertilizer/feedstock (55%) and metallurgical consumption (43%). Almost all recent sulphur imports are from Vancouver and in 2019 these amounted to US$68.7million.
Dangerous transport, expensive storage
Sulphuric acid with a minimum concentration of 77% is carried and stored in purposely constructed stainless steel tanks. Transport, handling and storage of sulphuric acid is high-risk and requires sophisticated and expensive containers and complex operating procedures.
Contact between water and sulphuric acid can generate a violent reaction and even the smallest spillage is dangerous to human health and the environment.
BHCP to produce elemental sulphur as prills
Cobalt Blue is planning a ground-breaking undertaking which will produce cobalt together with elemental sulphur co-product instead of corrosive sulphuric acid.
Capital costs for elemental sulphur recovery compare favorably with the much larger capital requirements of sulfide roasting and an associated acid making plant. Importantly, hazardous gas leak risks familiar to pyrometallurgical processing will be avoided in the planned BHCP development.
In order to enhance transport and marketing options a Canadian company, Enersul, recently used powdered sulphur produced from BHCP’s bench-scale trials to generate sulphur prills (refer photo). The prills are of high purity with more than 99% sulphur content.
Prill size and shape ensure that they have the smallest possible contact surface area and high bulk density. In bulk, prills behave like a fluid which is beneficial for transport, storage and further processing. The spherical and granular form enhances pouring/flowing qualities for distribution and handling.
Choosing to produce elemental sulphur has many advantages over acid. The movement, storage and handling of elemental sulphur prills is relatively straightforward, hence permitting and approval applications are simplified and distribution by road and rail has lower costs and is environmentally sensible.
Clearly, dependence on overseas supply and costs of both sulphur and acid are important commercial concerns for most industries and the BHCP will be well placed to address these to become a reliable domestic supplier.
Mitsubishi Corporation, a sizable global sulphur and sulphuric acid market trader, is supporting Cobalt Blue by undertaking market research.
Australian sulphur and acid market opportunities
Australia has vast undeveloped mineral deposits which could benefit from sulphuric acid processing and because it is adjacent to a main trunk rail line and state highway the BHCP is well located to supply these with sulphur.
Vast undeveloped phosphate deposits in central Australia such as the Verdant Minerals’ Ammaroo Project and Avenira’s Wonarah Project will access the Adelaide to Darwin rail line to target export markets in India and Asia and both could upgrade their phosphate ore to superphosphate and other fertilizer products using sulphuric acid processing.
Similarly, Australian metal deposits including many nickel, copper, rare earth and uranium projects require vast amounts of sulphuric acid for metal recovery and concentration. These are typically found in areas where liquid acid supply logistics are likely to be cost prohibitive.
BHCP elemental sulphur prills could be a game changer for many remote projects and a catalyst to future development of some.
Recent developments and future plans
Cobalt Blue is in the final stages of completing a pilot plant to produce more than 100 kilograms of cobalt battery chemicals as well as sulphur co-product. Commissioning is expected in early 2021.
Final products will be tested by Cobalt Blue’s commercial partners prior to construction of a larger scale demonstration plant and the undertaking of engineering and other technical studies in parallel with gaining approvals for BHCP development.
The project is undertaking State Significant Development Status and this will help streamline intended 2021 feasibility studies and subsequent project development.
Sulphur prills have similar shape and handling characteristics to coffee beans and both have distinctive tastes provided by sulphur compounds. Like coffee’s invigorating properties, sulphur will provide positive support for the project.