Late in 2013, Rio Tinto Alcan announced it would close down it's alumina refinery on the Gove peninsula of Australia's Northern Territory. I felt sad at this decision, although I understand the business decisions behind this. The reason for my sadness (as well as that of my wife) is that the years that we spent at Gove were some of the happiest of our lives.
Some background: alumina is the oxide of aluminium from which aluminium metal is smelted. The alumina is isolated as a pure compound from its chief ore, bauxite. Although alumina can be made from other aluminium sources such as clay, extraction from bauxite offers the easiest and most economical route. Bauxite can be thought of as what's left from a rock which contains aluminium after it has been subject to weathering over very long geological time periods under certain conditions of rainfall and temperature. The most economical bauxites to process tend to be found in tropical regions. Bauxites which contain the highest proportions of gibbsite, gamma-Al(OH)3 are the most highly prized, because they require less energy to process. The Gove peninsula is located only 11 degrees south of the equator, and the bauxite there has a high proportion of gibbsite.
Here's where Gove is located, relative to the rest of Australia:
It's a remote place. The original majority owner and technical manager of the mine and refinery Swiss Aluminium Ltd (or Alusuisse) made a documentary for their shareholders entitled "Keine Strasse Fuehrt Nach Gove" or "No Roads Lead to Gove", which was the truth. Everything that came into Gove came by sea via coastal freighter or barge or by air. The 4WD track out to Katherine was used by adventurous spirits travelling in convoy during the "dry" season (June to September).
For nearly six years, we called this place home, and we came to love it. My wife recalls that feeling of coming home as our plane bringing us back from leave flew over the bauxite mine, a hematite-red gash in the tropical woodlands.
As an amateur photographer, I loved the intensity of colour that the "wet" (monsoon) season brought, and I recall waiting for the bus to work in the mornings, gazing eastwards over the Arafura sea as the sun rose as a glowing orange ball, tingeing the gathering clouds which would later dump their cargo of rain in near-solid masses of water.
For me, there was fun to be had on two levels in Gove. There was the social aspect, where lots of mainly young people with young families came together. There were barbecues, dinner parties, and a lot of sport. In those early days at Gove, we made our own fun.
The second type of fun for me were the technical challenges. Although by profession I am a chemist, for the duration of the start-up of the plant I worked as a process engineer, responsible for starting up one of the unit processes of the plant. After a couple of years, I was asked to take over management of the process control laboratory.
So, how can you have fun in a place like this?
The first real challenge had to do with analytical chemistry, more specifically the analysis of the process liquor circulating in the plant. Let me explain the significance. The process used in alumina refineries around the world is called the Bayer Process, name after the Austrian chemist Karl Josef Bayer, who invented the alkaline route to the production of alumina in 1888. It's really a very simple process in principle. Bauxite is an ore containing mainly aluminium hydroxide and oxiyhydroxides, iron and titanium oxides, and silica in the form of kaolinite and quartz (fellow ex- and present alumina workers, please forgive this and following over-simplifications). The alumina values are separated from the other minerals by dissolving them with caustic alkali to form a supersaturated aluminate solution. After separation from the "red mud" gangue, the clear supersaturated aluminate solution is cooled and seeded with Al(OH)3. This causes some of the aluminate content of the liquor to decompose to Al(OH)3, which is then filtered, washed, and calcined at high temperature to alumina, Al2O3. The aluminate-depleted liquor is then recycled to dissolve more aluminium values from incoming bauxite. I'll talk about this in more detail in a later post. Essentially, the Bayer Process can be described in the reversible reaction:
Al(OH)3 + OH(-) <> Al(OH)4(-)
Our problem was in the manual, indicator-based titration method gifted us by the technology provider of the plant. Every operator-analyst saw the endpoint differently, and to add to the misery, the reaction behind the titration wasn't stoichiometric. The net effect that the production department didn't trust the results the lab. was issuing, and wouldn't run the risk of driving the process to the point where it was most efficient and where the profits are made.
A predecessor of mine had purchased, but never put the effort into implementing an early type of thermometric titrator. I saw it as our last best hope of solving the problem. Given that all my lab. supervisors were flat out with their daily tasks, it fell to me to do the development work necessary. Being a stubborn fellow, I kept at it until I felt I had a viable method. Then came the really difficult bit. We had to prove that it would actually control the process. We did lab. experiments on mass balances, and then tracked the process in parallel with the existing liquor analysis procedure. We proved we could predict the bauxite charge to within 1 tonne in 150, while the existing procedure couldn't close mass balances, and couldn't predict anything worthwhile. Still, we had to overcome opposition and even some hostility from the production and process engineers. I was later reminded of something the great Italian management advisor Niccolo Machiavelli wrote in his work "The Prince": "It should be borne in mind that there is nothing more difficult to handle, more doubtful of success and more dangerous to carry out than initiating changes (in a state's constitution). The innovator makes enemies of all those who prospered under the old order, and only lukewarm support is forthcoming from those who would prosper under the new". Substitute "analytical method" for "state's constitution" and you get my drift.
We persevered, and unwittingly at the time, provided the analytical tool that would permit the successful implementation of a radical change in the process necessitated by the world demand for a change in the type of alumina required by modern smelters. I'll talk about the laboratory's role in this new process in a later blog.
There are a couple of footnotes. Firstly, I was told some years later that the change in the analysis procedure had been responsible for the production of an extra 50,000 tonnes of alumina per annum with no additional process costs. At a then price per tonne of approximately US$ 200, I'll let you do the math on the positive benefit to the bottom line of the company. Secondly, this positive experience with thermometric titrimetry led me years later to co-develop a modern, computer-driven automated thermometric titration system, whose enabling technology is now incorporated in the Metrohm 859 Titrotherm.
Some background: alumina is the oxide of aluminium from which aluminium metal is smelted. The alumina is isolated as a pure compound from its chief ore, bauxite. Although alumina can be made from other aluminium sources such as clay, extraction from bauxite offers the easiest and most economical route. Bauxite can be thought of as what's left from a rock which contains aluminium after it has been subject to weathering over very long geological time periods under certain conditions of rainfall and temperature. The most economical bauxites to process tend to be found in tropical regions. Bauxites which contain the highest proportions of gibbsite, gamma-Al(OH)3 are the most highly prized, because they require less energy to process. The Gove peninsula is located only 11 degrees south of the equator, and the bauxite there has a high proportion of gibbsite.
Here's where Gove is located, relative to the rest of Australia:
It's a remote place. The original majority owner and technical manager of the mine and refinery Swiss Aluminium Ltd (or Alusuisse) made a documentary for their shareholders entitled "Keine Strasse Fuehrt Nach Gove" or "No Roads Lead to Gove", which was the truth. Everything that came into Gove came by sea via coastal freighter or barge or by air. The 4WD track out to Katherine was used by adventurous spirits travelling in convoy during the "dry" season (June to September).
For nearly six years, we called this place home, and we came to love it. My wife recalls that feeling of coming home as our plane bringing us back from leave flew over the bauxite mine, a hematite-red gash in the tropical woodlands.
As an amateur photographer, I loved the intensity of colour that the "wet" (monsoon) season brought, and I recall waiting for the bus to work in the mornings, gazing eastwards over the Arafura sea as the sun rose as a glowing orange ball, tingeing the gathering clouds which would later dump their cargo of rain in near-solid masses of water.
For me, there was fun to be had on two levels in Gove. There was the social aspect, where lots of mainly young people with young families came together. There were barbecues, dinner parties, and a lot of sport. In those early days at Gove, we made our own fun.
The second type of fun for me were the technical challenges. Although by profession I am a chemist, for the duration of the start-up of the plant I worked as a process engineer, responsible for starting up one of the unit processes of the plant. After a couple of years, I was asked to take over management of the process control laboratory.
So, how can you have fun in a place like this?
The first real challenge had to do with analytical chemistry, more specifically the analysis of the process liquor circulating in the plant. Let me explain the significance. The process used in alumina refineries around the world is called the Bayer Process, name after the Austrian chemist Karl Josef Bayer, who invented the alkaline route to the production of alumina in 1888. It's really a very simple process in principle. Bauxite is an ore containing mainly aluminium hydroxide and oxiyhydroxides, iron and titanium oxides, and silica in the form of kaolinite and quartz (fellow ex- and present alumina workers, please forgive this and following over-simplifications). The alumina values are separated from the other minerals by dissolving them with caustic alkali to form a supersaturated aluminate solution. After separation from the "red mud" gangue, the clear supersaturated aluminate solution is cooled and seeded with Al(OH)3. This causes some of the aluminate content of the liquor to decompose to Al(OH)3, which is then filtered, washed, and calcined at high temperature to alumina, Al2O3. The aluminate-depleted liquor is then recycled to dissolve more aluminium values from incoming bauxite. I'll talk about this in more detail in a later post. Essentially, the Bayer Process can be described in the reversible reaction:
Al(OH)3 + OH(-) <> Al(OH)4(-)
Our problem was in the manual, indicator-based titration method gifted us by the technology provider of the plant. Every operator-analyst saw the endpoint differently, and to add to the misery, the reaction behind the titration wasn't stoichiometric. The net effect that the production department didn't trust the results the lab. was issuing, and wouldn't run the risk of driving the process to the point where it was most efficient and where the profits are made.
A predecessor of mine had purchased, but never put the effort into implementing an early type of thermometric titrator. I saw it as our last best hope of solving the problem. Given that all my lab. supervisors were flat out with their daily tasks, it fell to me to do the development work necessary. Being a stubborn fellow, I kept at it until I felt I had a viable method. Then came the really difficult bit. We had to prove that it would actually control the process. We did lab. experiments on mass balances, and then tracked the process in parallel with the existing liquor analysis procedure. We proved we could predict the bauxite charge to within 1 tonne in 150, while the existing procedure couldn't close mass balances, and couldn't predict anything worthwhile. Still, we had to overcome opposition and even some hostility from the production and process engineers. I was later reminded of something the great Italian management advisor Niccolo Machiavelli wrote in his work "The Prince": "It should be borne in mind that there is nothing more difficult to handle, more doubtful of success and more dangerous to carry out than initiating changes (in a state's constitution). The innovator makes enemies of all those who prospered under the old order, and only lukewarm support is forthcoming from those who would prosper under the new". Substitute "analytical method" for "state's constitution" and you get my drift.
We persevered, and unwittingly at the time, provided the analytical tool that would permit the successful implementation of a radical change in the process necessitated by the world demand for a change in the type of alumina required by modern smelters. I'll talk about the laboratory's role in this new process in a later blog.
There are a couple of footnotes. Firstly, I was told some years later that the change in the analysis procedure had been responsible for the production of an extra 50,000 tonnes of alumina per annum with no additional process costs. At a then price per tonne of approximately US$ 200, I'll let you do the math on the positive benefit to the bottom line of the company. Secondly, this positive experience with thermometric titrimetry led me years later to co-develop a modern, computer-driven automated thermometric titration system, whose enabling technology is now incorporated in the Metrohm 859 Titrotherm.