Colonial Coal Mining
The story of the Rotowaro Carbonisation Works is integrally linked to that of coal mining as an allied operation designed to reduce waste and increase profitability without increasing the onus on workers. Many of the workers came from jobs in the adjacent coalfield and lived at Rotowaro Township, the lives of both workforces and their families were integrally entwined. For this reason the growth and changes to colonial coal mining are outlined here to set the scene for detail of such a coal slack processing plant.
Early coal mining activity was largely focused on the South Island's West Coast and as with elsewhere in the world, the nature of the industry meant that the miners lived in coal towns established around the mining activity or in satellite camps. The miners of colonial New Zealand largely lived in their own world in environments that were both harsh and inaccessible, unlikely to have been developed, but for the coal seams. The degree of isolation and remoteness was not as marked with the development of the Waikato and Otago/Southland coalfields. As transport improved so miners were able to move on to more diverse towns such as Greymouth and Huntly. As migrants, these transplanted British colliers also suffered isolation, driven by fear from the colonial coal masters of the late 1870s of 'the twin evils of Methodism and unionism'. Confirmation of this status saw the miners labelled as outsiders who lacked the 'pride of colonials' described at the time as having, 'lower ideas of life', 'inferior morals and stronger prejudices' than the general population. They became isolated by nationality as well as occupation, even in the 1940s when coal towns were noted for a discordant 'foreign twang'. Although the coalfields had a male dominated work force, many miners brought families to New Zealand with them and their wives were often from mining families and had worked above ground in British coalmines.
Early mining in New Zealand was owned and operated by private operators with shipping companies monopolising this through absentee owners. Over time, government support, encouraged by the colliers, was viewed by owners as interference. Government involvement gradually moved to actual investment in mining companies and ultimately to nationalisation of the industry. For the miners, despite many failed attempts, it was not until 1923 that a national body, the United Mine Works formation was established as a coherent response to wage cuts in1922-3. For miners in bigger towns such as Huntly establishment of a local borough council in the first decade or the twentieth century became an opportunity for union influence, as did school committees.
Early living conditions in the towns and camps supporting coal mines, were insanitary and few homes reached a standard of comfort in city homes of blue collar workers. Government looked to the coal towns of the Waikato fields to change this situation. There were shortages and rents were believed to be too high, but at Rotowaro and Pukemiro it was seen as possible for these to be made into 'extremely attractive garden villages' and for Huntly having the potential to becoming a 'model suburb'.
The rapid growth of the dairy industry and associated factory demands along with the expansion of domestic and industrial markets in the booming Auckland area, were the major factors for the amalgamation and expansion of the existing pits in the Waikato, by the Taupiri Coal Company. Begun in 1876, coal production in the Waikato increased by 400 per cent by 1914 and its share of the national product had risen from 7 to 15 per cent. This trend gathered momentum and by 1935 Waikato had eclipsed the West Coast as the leading coal centre at the expense of Otago Southland. Mostly migrants, nearly 2,000 newcomers made this growth possible.
Turning Waste to Profit: Coal Waste Processing Plants
Prior to the construction of the Rotowaro Carbonisation Plant, briquette producing plants were constructed at some collieries to utilize the slack coal that otherwise had to be dumped as waste. The disposal of slack coal had already been recognised as a matter of national importance as early as 1891. Around that time, construction of a briquette plant seems to have started at the site of the Brunner mine. However, this project was abandoned before it was finished. In 1892 a briquette manufacturing plant that belonged to the Grey Valley Coal Company was operating in Christchurch. According to a contemporary newspaper account this was the only machinery of its kind in the Southern Hemisphere at the time. The plant was situated in the south-east corner of the city. It produced six ton of briquettes per day with demand outstripping supply. In 1906 a briquetting plant was constructed at the Seddonville State Mine. In 1909 a briquette plant was operational near Westport processing slack from the nearby Stockton coal mine. This may refer to the same plant since the newspaper article mentions the arrival of an expert to introduce a new process in coal briquetting. In December 1912 this facility was dismantled after the lease of the site expired.
The most significant works established in New Zealand to turn slack coal in to profitable product was established at Rotowaro Coalfield.
The Inception of the Carbonisation Works
The rapid growth and success of the Waikato Coalfield, provided the company with the not only the ability but also the necessity to invest in establishing a coal slack processing plant. The Rotowaro Carbonisation Works was established to dispose of the huge amount of waste coal (slack) that was generated at the Rotowaro Mine that had been operated by the Taupiri Coal Mining Company since 1917. Because of its size the slack was commercially unviable to sell and large quantities had to be dumped to meet demand for the screened grade of coal.
It not only required the availability of extensive dump areas, but also presented a significant fire hazard and was an enormous waste of a potential energy source. The coal commonly mined in the Waikato tends to disintegrate on exposure to weather. Thus nearly 45 percent of all coal mined ended up as slack waste after having passed through a three-quarter inch (1.905 centimetre) square mesh screen. As a result, in the Waikato alone, around 150,000 tons of slack coal was produced annually. Even though the Auckland Power Boards' steam generating station at Kings Wharf used about 80,000 tons of that, it still left the region with a significant amount of coal waste to deal with.
Investigations into other uses for the slack were also instigated by the anticipated effect the governments hydroelectric power scheme would have on the market for slack coal. It was widely known that the Kings Wharf steam generating station would be closed once the Arapuni Hydroelectric station was brought online. This would result in the loss of a major client for the Waikato coal mine owners. Therefore they began to investigate English and continental systems of coal processing that would turn slack into a commercially viable product.
At an early stage coal carbonisation was considered to be an option and by 1923 various carbonisation processes were investigated.
Subsequently, in 1924 a small experimental carbonette press was acquired and experiments using New Zealand coal were carried out. It soon became clear that New Zealand coal was not suitable for producing carbonettes without a binding agent. Other issues identified were suitable heaters for the moulds, the size of the coal, the nature and amount of binders required and the pressure required for moulding carbonettes.
In 1925 Waikato coal was sent to England, Belgium and Germany for trialling in a number of processes so as to obtain a report on its suitability for carbonisation. The German trials turned out to be the most favourable. Earlier research of coal processing technologies carried out by the government had already indicated that the coal mined at the Waikato mines had characteristics similar to German coal.
Choosing a Carbonisation Technology and Purchasing a Plant
As a result of these series of experiments and trials the German Lurgi process was chosen. This process was owned by the Metallgesellschaft AG based in Frankfurt, Germany. The Lurgi process was the most common carbonisation process in use at the time for processing lignite, the lowest grade of coal and the type mined in the Waikato at the time. It is brownish-black and has a high inherent moisture content. The process was in use in Canada, the USA, Greece, Hungary and Germany.
The Lurgi process uses externally heated steel retorts for low-temperature (max. 650° Celsius) carbonisation to improve the quality of the fuel, creating virtually smokeless carbonettes. This was achieved in three steps.
1. Coal slack was carbonised at a low temperature to leave between 7 and 10 percent of volatile matter, thus creating a semi-coke.
2. As by-products tar, oil and pitch were produced.
3. Carbonettes were created from the semi-coke using the pitch created as a by-product as part of the binder required.
The aim was to produce a high-grade, smokeless fuel that would be useable for railway and domestic purposes and also for power plants. It was foreseen that 40,000 tons of high grade carbonettes, 2000 tons of diesel oil, 320 tons of fuel oil and 2900 tons of pitch could be produced per year. In 1929 the Waikato Carbonisation Ltd was set up as a subsidiary of four local coal companies. It was responsible for the processing of the coal slack and returning the revenue back to the coal companies.
A slack processing plant was acquired from the Lurgi Metallgesellschaft to be erected near the Rotowaro mine. There it could handle all slack coal produced at the Taupiri Company mines efficiently. If necessary, additional slack would be available from the nearby Pukemiro and Renown mines. Before making the final decision regarding the purchase of the plant the mining companies were promised that the Railway Department would purchase substantial amounts of carbonettes once the plant was running. This undoubtedly had an influence on the decision to buy the plant.
The Construction of the Plant
In November 1929 D.G. Whitwell arrived in New Zealand to make preparations for the construction of the plant. He was the main engineer in charge and represented Fuel Industries Ltd who owned the British rights to the Lurgi Process. In the same year W.G. Heptinstall, a Canadian engineer, was appointed manager of the Rotowaro Carbonisation Works. He was a very experienced engineer, having been in charge of the Lurgi Carbonisation Plant in Saskatchewan, Canada.
The main parts of the plant were shipped from Europe in February 1930. August Finkenbeiner, a representative of the Metallgesellschaft accompanied the plant to supervise its construction. He was later joined by a second engineer, Mr Müller, who not only assisted in the supervision of the plant but was a carbonisation expert also.
The plant arrived on 22 April 1930 on the Ruahine. Since the New Zealand government recognised the importance of the plant and the need for its technology, most was landed duty free. One hundred railway wagons were needed to transport the plant from Auckland to Rotowaro. In addition to the material purchased from the Lurgi Metallgesellschaft, several parts needed to be constructed in New Zealand. These included the hoppers for the Retort Building, the steam boilers, the various bunkers, the bricks and the conveyors.
It took almost a year and 60 New Zealand staff to erect the plant. In May 1931 the plant started operating on an experimental basis. On 10 June 1931 the plant was officially opened by the Hon. W.A. Veitch, the Minister of Railways and the Hon. A.J. Murdoch, Minister of Mines. The opening was attended by around two hundred guests, many having travelled from Auckland on a train powered by carbonettes produced at the carbonisation works. Among the guests were members of parliament, leading business and industrial figures and local government representatives. At its opening the plant was hailed as a major technological advance and it was stated that it would be the first of many plants that would serve the coal mining centres. However, it would remain the only low temperature carbonisation plant in New Zealand. It was not until 1958 that another low temperature carbonisation plant was built in the Southern Hemisphere. Research has shown that although some Low Temperature Carbonisation plants using the Lurgi technology are still operational elsewhere in the world these are all of a much later date. All plants contemporary to the Rotowaro Carbonisation Plant have been closed and subsequently demolished.
The Initial Years of Carbonette Production
Predictions about the level of demand for carbonettes were not initially realised. The main factor that impacted on the reduced demand, production and operational ability of the plant was the Great Depression and ironically, at a time when creation of employment was so crucial, this lack of demand meant that the plant was only able to operate for six months of the year through to 1934. However, the mining operation was also reduced during that period, to two or three days a week, thus significantly reducing the amount of slack coal produced. This situation did not help the struggling Carbonisation Works, which made barely enough money to pay for its operating expenses. Despite these difficult circumstances a second carbonette bunker was erected in 1933 to increase cooling capacity.
In 1934 the Railway Department failed to renew its contract after tests had shown that the carbonettes were not suitable for its locomotives. It seems however, that this decision was, at least to some extent, governed by the relatively high cost of the carbonettes compared to the normal sized coal the Waikato mines produced.
The government took notice of the situation the Carbonisation Works was in. It also realised that large amounts of slack were still being wasted and in 1935 the Hon. P.C. Webb, Minister of Mines, stated in his annual report that: 'the unnecessary wastage of coal has always given me the greatest concern'. Subsequently, in an attempt to increase demand the government started an intensive advertising campaign for carbonettes in 1935. At the same time, in an effort to try and to minimize the amount of coal wasted, screens with a smaller mesh were installed at the Carbonisation Works to increase the amount of slack coal being processed. The advertising campaign resulted in the demand for carbonettes increasing to 17,000 tons in 1936 and 21,000 tons in 1937. From 1937 the demand outstripped the supply of slack coal and thus solved that problem for the Waikato mines. From 1936, carbonettes were sold at Woolworths in cardboard boxes. Initially, carbonettes were also shipped to Nelson, Dunedin and Bluff, but this practice was discontinued when demand in the North Island could not be met.
In 1936 a gas engine generator was installed to generate part of the electricity demand of the factory.
From 1936 the plant operated for 10 months a year. The remaining two months a year were necessary for staff holidays and maintenance. When both retorts were operating it took 60 men to keep the plant running. The men worked in a shift system, since it was necessary to keep the plant going for 24 hours a day, seven days a week because starting and shutting down the plant each took between 10 and 14 days. The average employee worked 42 hours a week, receiving higher rates for Saturday and Sunday shifts.
During the initial period the markets for the by-products were very slow. Light oil was distilled in the tar distillation plant and used as a weed killer and fuel oil. Initially, the tar produced yielded about 30 per cent of the pitch required for the carbonisation process. The additional pitch needed for the production of carbonettes was imported from Trinidad. In 1938 the original tar distillation equipment, which by then had become seriously corroded, was replaced with a Wilton continuous pipe still. This increased the tar production to about 70 per cent of pitch required for the production of the carbonettes. That same year the company was awarded a contract to provide creosote for the timber treating plant built by the Forestry Department near Rotorua. This turned the production of the heavy distillates into a profitable business. Additionally, during the war substantial quantities of creosote were exported to India and large quantities were used in New Zealand for the preservation of sand bags used for defence purposes.
During World War Two petrol shortages led to the manufacturing of gas producers to power private cars and trucks. To meet the demand for fuel for these, the company marketed its char under the name 'Waicarbo' which was subsequently sold all over New Zealand. At its peak production reached 1000 tons a month.
Production Post War
With the end of World War Two the demand for 'Waicarbo' stopped, and was replaced with a similar, but larger, fuel developed and sold under the name 'Raycarbo'. This was mainly used for 'Esse' stoves and heaters. Although the demand for Raycarbo never increased above circa 800 tons a year, by this time the carbonettes had become very popular as a household fuel and for commercial use in bakers ovens and sales remained steady between 1946 and 1960.
By the mid 1950's the plant produced a range of products: carbonettes, screened carbonised coal, creosote, pitch and gas. By 1956 the government owned two thirds of the company, the other third was owned by Pukemiro Collieries. A drop in sales in 1962 was countered with another extensive advertising campaign and sales returned to levels previously achieved.
In 1964 the economic life of the 1930's retorts came to an end and investigations were undertaken looking into replacing the plant. Lurgi came up with an offer of a new plant with three new retorts including a treatment facility for phenol solvents with a cost estimate of around 20 million German marks. The price was probably deemed too high since this offer was never followed up. In 1968 the plant became solely government owned under the State Coal Mines Department. By 1974 the demand for carbonettes had fallen again but this was offset by demand for char by New Zealand Steel Ltd for its steel production process.
The First Explosion in the Plant
On 7 March 1974 an explosion occurred at the distillation building. The explosion was described as looking 'like a volcano erupting from Huntley, nine miles away'. Another witness, reportedly working nearly half a mile (800 metres) away felt a blast of hot air on his back. When he looked around he saw a fireball rising to 400 feet (120 meters) in the air. The explosion seriously wounded one man, who died later in hospital, and set several nearby buildings on fire. The still building was gutted and the main retort building was severely damaged. Although repairs were undertaken immediately the production of carbonettes, creosote and pitch had to be stopped, the production of char for New Zealand Steel continued though.
Upgrading the Plant
In 1976 Lurgi Metallgesellschaft was again asked for a quote for replacing the retorts, but no action was undertaken. The following year plans were prepared to replace the entire plant with a modern Australian char plant of similar capacity as by now char was the most important product manufactured at the plant. This idea was abandoned in favour of a partial upgrade of the complex. Work carried out included the reconstruction of one of the retorts, the installation of new tar recovery machinery and new carbonisation machinery. This was carried out in between 1979 and 1981 for a total cost of 1.4 million dollars.
In 1981 a wood charcoal barbecue briquette production facility was built near the No 2 carbonette bunker and screening plant. However, this did not prove to be an economic success. In 1986 the production of carbonettes stopped permanently. The plant continued to produce Raycarbo fuel for the domestic market, char for New Zealand Steel and creosote for Railways for the treatment of railway sleepers.
In 1985 the building known as the Rotowaro Carbonisation Works Adit (also known as the Mine ventilation Fan Structure) was registered as a class C building (Record no. 4282). At the same time the Store Shed (or Loco Shed) was registered as a class C building (Record no. 4283). In 2001 both were changed to Historic Place Category II registrations. These buildings were not a part of the Carbonisation Works, but of the Rotowaro Industrial Precinct located to the northeast. These buildings were both related to the actual mining activities carried out at the nearby underground Rotowaro Mine.
The Second Explosion in the Plant and its Subsequent Closure
In 1987 another explosion occurred at the plant, this time at the retort building, followed by a major fire. Operation of the plant ceased while options were being considered. Although the company was insured adequately for the repairs to be carried out, new safety regulations meant extensive changes were necessary for production to resume. The decreased demand for Raycarbo and char made new investments economically unviable and subsequently it was announced on 24 July 1987 that the plant would cease operations permanently on 7 August 1987. At the time of closure it employed 25 workers and management staff. Following closure the company went into liquidation. This left the workers without any redundancy payments and it took until September 1994 before the government finally decided on a $1500 ex gratia payment to those workers.
The workers' attitude towards the Carbonisation Works has always been ambiguous and changed over time with the changing attitudes towards health and safety issues. In the early days the emissions from the works, although smelly and dusty, were supposedly healthy and it was said that anybody suffering from the whooping cough just had to be sent to the plant and that would cure them. Others called it 'the filthiest place that was ever made' and complained about the black, greasy sort of dust it emitted which was almost impossible to clean off. However, the carbonettes it produced were a great success, especially with the workers getting them for nothing or at a very low price. With regards to the safety issues one interviewee casually remarks that starting the plant was 'rather a dicky business'. The general public's view of the place has also been one of extremes over the years. For some it is 'Waikato's number one environmental problem' that should be completely cleaned up. Others have documented the works for exhibition purposes or as part of an art and design course.
The Rotowaro Carbonisation Works as a whole was registered in 1991 (Record no: 7013). Subsequently, in 1992, two buildings within this historic area, the Main Structure (the Retort Building) and the No 2 Screening Structure and Bunker were registered as Category I Historic Places (Record nos. 4171 and 4172 respectively).
Since its closure the Rotowaro Carbonisation Works has been targeted by looters and thieves. Metal as well as wooden parts have been removed from the various buildings. The main building targeted has been the No 2 Screening Structure and Bunker. This building, mainly constructed out of wood, has had large timber sections removed over the years. Other buildings have had metal parts such as its cladding and machine parts removed, probably to be sold as scrap metal. After the creation of the bund (see below) the looting has diminished somewhat, as the ponded water makes it harder to get to the structures. However, even though the looting has affected some buildings more than others it has not compromised the overall integrity of the plant or destroyed essential elements that communicate how the plant operated.
Cleaning up the Site
Soon after the company went into liquidation appeals were made to clean up the site. It was recognised that over the years it had been allowed to spread it contamination beyond its 10 ha site without constraint because the plant started operating long before the Town and Country Planning Act of 1958 and the Water and Soil Act of 1967 and so was not subject to any controlling authority. It meant that the Carbonisation Works could, after the introduction of both these laws, quite legally get by on its existing use right and keep discharging any waste of cooling water into the Awaroa Stream. Even after 1976, after a water right was issued to allow for these practices, little attempt was made to clean up the discharge before it entered the stream. Even when a fine was issued, this did not improve the situation because 'it wasn't a particularly big fine'. When in 1981 the water right expired and was not renewed, the company did stop discharging into the stream and started a waste incarceration programme. Its capacity proved inadequate and the company began storing the waste on site thereby creating three ponds that eventually overlapped to create one big pond measuring about 2000 m2. The company tried to use micro organisms to reduce the toxicity of the ponds, but that failed because of the sheer volume of toxic waste produced.
After the company went into liquidation some work was done to minimise the risk posed by the ponds. These consisted mainly of shoring up the sides of the ponds and roofing them over to prevent rainwater getting in and causing overflow. However, over the years the banks started showing signs of seepage and collapse and by late 1990, shortly after the elections brought in a National government, it was decided that action had to be taken. The previous Labour government had rejected the idea of a clean-up following advice from the Treasury department saying that the government was not legally responsible for the site. During the election run-up, the local National candidate had promised that 'Waikato's number one environment problem' would be cleaned up. Initially the National party seemed to back out of their promise, but it decided in December 1990 to ignore Treasury's advice and agreed to fully fund a cleanup operation.
Waikato Regional Council (now Environment Waikato) drew up a plan for the cleanup and managed the actual work on behalf of the Crown. This cleanup started in early 1991. Liquid from the ponds was pumped into trucks and carried off to the Kinleith Pulp and Paper Mill in Te Kuiti, where it was incinerated. In total about 11,000 cubic metres of stored liquid was removed. The empty ponds were subsequently filled with the remaining liquids, totalling about 4000 cubic metres. This sludge was treated by means of bioremediation, the first time this was carried out in New Zealand. Extra nutrients and air were added to the mixture to stimulate bacteria to break down the contaminants. By August 1995 this resulted in about 500 cubic metres of relatively dry, inert material. This was mixed with clay, locally spread over land, covered with clay and contoured to direct any runoff away from the Awaroa Stream.
Expansion of the Nearby Opencast Mine and Creation of the Bund
From 1992 onwards Coal Corp expanded the opencast mine to the east and south-east of the carbonisation works. As a result of the expansion the nearby Rotowaro Industrial Precinct was completely destroyed. This was the location where the two category II buildings were located. The expansion covered part of the registered Rotowaro Carbonisation Historic Area, destroying several buildings, including the fitters workshop and the new storeroom. It also destroyed the footprint of a number of buildings that had already been demolished by then, such as the old staff lunchroom, the electric shop, the old administration office, the weigh bridge and the old laboratory. The overburden that was removed to get to the underlying coal was used to create a bund around the site. The bund was created by digging a key into the underlying stable clay deposits and filling this in with the overburden material. The purpose of the bund was to prevent contaminated water running into the Awaroa Stream. As a result the bunded area flooded with water up to 2 metres deep, thereby effectively prohibiting access to the buildings.
This was an undesirable environment for the steel buildings to be subjected to, especially since the water table fluctuated throughout the year. Therefore, it was decided in 1995 to insert a drain in the bund for water to be released into the adjacent Awaroa Stream. However, the drain was not opened until late 1998 or early 1999. Water testing was carried out and the water was not deemed to be an environmental problem. This alleviated the water problem somewhat although during wet periods the site is still partially inundated.
Since 2003 new steps have been undertaken to identify methods to remove the remaining contaminants from the site and to identify means to stabilise the heritage structures and elements of the plant. The goals of this remediation were to ensure that the site does not have a significant adverse effect on the Awaroa Stream, to ensure that the site should no longer pose an unacceptable risk to the public and to reduce the rate of deterioration of the structural elements by identifying methods of stabilisation. For that purpose a study was undertaken in 2007 funded by the Ministry for the Environment, the NZHPT and Solid Energy New Zealand. As a result, a remediation action plan is currently being produced that will be undertaken during the summer of 2008-09.
Comparative Analysis
The Rotowaro Carbonisation Works was the first plant of its kind in New Zealand and despite intentions otherwise, it remained the only one that was built. The Lurgi low temperature coal carbonisation process was in use in several countries worldwide in the period between 1920 and 1950. In some countries it is still being used today, albeit with variable success.
Europe
Germany
Although the process originates from Germany only one example of a carbonisation plant using the Lurgi process has been found. In 1935 a brown-coal processing plant was built in Espenhain, near Leipzig. The main purpose of the plant was to generate power for Germany's heavy industries. To maximise the amount of coal used the plant applied the Lurgi-spulgas technique to manufacture carbonettes from the slack coal. These would then be used as a fuel in power plants generating electricity and steam. After World War Two the plant came under Soviet control and even became a Soviet company until 1954. The plant produced large amount of tar, cokes and oil products for over 50 years. In the 1980's environmental awareness led to large public protests because of the pollution caused by the outdated equipment. Just prior to the German Reunification the socialist German Democratic Republic decided in February 1990 that all carbo-chemical systems in the Republic should be closed. On 27 August 1990 the plant at Espenhain was closed down. It was replaced in 2004 by a solar power plant; the biggest in Europe at the time of its construction. At the start of World War Two twelve brown-coal processing plants were operational in Germany. These used the low temperature carbonisation process to make synthetic fuel, in order to make Germany independent from foreign supply for its war efforts. However, these did not manufacture carbonettes for the domestic market and no longer exist.
The United Kingdom
No references have been found to carbonisation plants using the Lurgi technique in the United Kingdom. At the time the Rotowaro Carbonisation plant was first considered research showed that carbonisation technologies used in the UK were not suitable for coal found in the Waikato. This suggests that the Lurgi technique is not suitable for coal deposits commonly found in the UK. In the beginning of the twentieth century several coal carbonisation plants were constructed. However, most of these did not produce carbonettes for the domestic market, but rather gasified coal to supply power houses and towns with gas. The Phurnacite plant in Abercwmboi, Wales, operated in a way similar as the Rotowaro Carbonisation Works. The Phurnacite plant was opened in 1939, in an area that had been mining coal successfully since 1851. Like at Rotowaro, waste coal was crushed, dried and mixed with pitch to produce carbonettes. The Phurnacite plant produced approximately 1 millions tons of carbonettes per year during its peak. By the mid 1970's demand dwindled for carbonettes and awareness of its environmental impact caused the plant to be closed in 1991, after an attempt to upgrade the plant had failed. Since it was closed the plant has been destroyed.
Australia
In 1929 in the Gelliondale Briquette Plant was constructed in Victoria. The plant did not carbonise coal slack; instead it produced briquettes by binding raw coal slack with pitch. This plant produced briquettes between 1934 and 1944. In 1950 the plant was closed down. Today only some of the footings remain. In October 1956 a Lurgi Gasification Plant was opened at Morwell, Victoria. The Lurgi process was selected because the by-products were expected to improve the economic returns of the plant. However, this plant did not produce carbonettes for the domestic market, rather producing 15,000,000 cubic feet (424752.7 cubic metres) of gas per day to supply Melbourne with town gas. The plant ran until 1970 when it became economically unviable due to the advent of natural gas.
North America
In 1920 a carboniser with auxiliary buildings was constructed by the Canadian Lignite Utilization Board near Bienfait, Saskatchewan, Canada, between two major collieries, the Western Dominion Colleries and the Manitoba and Saskatchewan Coal Company of Winnipeg. This plant became operational in 1921 but none of the carbonizing processes used were successful, forcing closure in 1923. In 1929 a Lurgi plant was erected in Black Diamond (Alberta, Canada) under supervision of German engineers. The plant went into production in 1930 and although good quality briquettes were produced they would burn from spontaneous combustion during storage. Since this problem could not be solved the plant was shut down. The plant was bought by John H. Macdonald of Winnipeg who, with help from three hands from a Lurgi plant in Dickinson (North Dakota, USA), managed to run it successfully until 1963. Subsequently the plant was sold on again and it successfully produced char until 1982, when it was shut down permanently. The only Lurgi plant located in the USA known to have produced carbonettes is the one in Dickinson. No further information has been obtained about this plant. In 1984 a coal gasification plant started operating near Beulah, North Dakota. This plant uses the Lurgi technique to produce natural gas. It also produces many by-products and is running profitably. Currently this is the only commercial coal gasification plant operation in North America.
India
At least two carbonisation plants have been built on the Indian subcontinent, one in Neyveli and one in Dankuni. The one in Neyveli was part of a larger complex of power stations and coal processing plants located on one of the largest Lignite coal reserves of India. The briquetting and carbonisation plant was built in 1966 using equipment supplied by a consortium of West German firms. As with the other low-temperature carbonisation plants the by-products were an important argument to build the plant. This plant stopped operating in 2001. The Low Temperature Carbonization (LTC) plant in Dankuni was commissioned in 1990 but has been incurring losses since it started operating. Coal India has been trying to sell this plant for a number of years now but so far no serious buyer has been found.
