A new technology characterized by rapidly non-mechanical settlement of unclassified tailings was developed based on a large number of tests, and dynamic settlement and continual slurry preparation without hardening in...A new technology characterized by rapidly non-mechanical settlement of unclassified tailings was developed based on a large number of tests, and dynamic settlement and continual slurry preparation without hardening in vertical sand silo were eventually realized by the addition of an effective flocculating agent (NPA). The results show that the sedimentation velocity of interface between unclassified tailings and water after the addition of NPA increases by 10-20 times, the sedimentation mass fraction of unclassified tailings at the bottom of vertical sand silo is up to 64%, the solid particle content of waste water meets the national standard, and the side influences of NPA can be removed by the addition of fly ash. The industrial test result shows that the system, the addition manner and the equipments are rational, and the vertical sand silo is used efficiently. This developed system is simple with large throughput, and the processing cost is 2.2 yuan(RMB)/m3, only 10%-20% of that by mechanical settlement.展开更多
Vast amounts of tailings are produced daily in bitumen extraction from the Athabasca oil sands. The coarse sand from the tailings stream is used to build dykes around the containment basin. The run off slurry arrives ...Vast amounts of tailings are produced daily in bitumen extraction from the Athabasca oil sands. The coarse sand from the tailings stream is used to build dykes around the containment basin. The run off slurry arrives at the water’s edge in the tailings pond at a solids concentration of about 3%～8% by mass. Settling of the solids takes place "relatively fast", over several days, creating a "free water zone" that contains little solids. When the fine mineral solids concentration has reached about 15% by mass, the suspension develops non Newtonian properties. After 2～3 years, the suspension concentration reaches a value of about 30% by mass at which the settling rate becomes extremely slow. Methods to handle the already created tailings ponds and new approaches to eliminate the creation of new ones will be discussed both from the industrial and fundamental prospective.展开更多
The objectives of this experiment were to evaluate the performance of different plant species growing in different kinds of oil sands fine tailings,and to estimate the uptake of organic contaminants by plants from the...The objectives of this experiment were to evaluate the performance of different plant species growing in different kinds of oil sands fine tailings,and to estimate the uptake of organic contaminants by plants from the oil sands fine tailings.In general,total hydrocarbon in the plant could be ranked(beginning with the highest)as:unweathered plant 4 tailings (UWT),Freeze Thawtailings(FT),weathered plant 4 tailings(WT),and consolidated tailings(CT) for the willow,poplar and cattails.For grass,CT amended with tailings sand and muskeg had the highest hydrocarbon level in the field treatment,however,other three kinds of tailings(FT,WT and UWT) had lower but similar to each other hydrocarbon levels.展开更多
In the oil sands industry, high temperature with the addition of a caustic dispersing agent has formed the basis of the Clark hot water extraction process used successfully on a commercial scale to recover bitumen fro...In the oil sands industry, high temperature with the addition of a caustic dispersing agent has formed the basis of the Clark hot water extraction process used successfully on a commercial scale to recover bitumen from surface mined oil sands ore since 1967. Processes different from the established Clark process （high temperature and caustic） have been developed to work at a range of temperatures with or without the use of sodium hydroxide. Large scale bitumen extraction pilot tests were performed with two different extraction processes and large strain consolidation tests were performed on the resulting different railings. These consolidation tests determined the compressibility and hydraulic conductivity relationships with void ratio which are engineering properties that influence the long-term disposal of the fine tailings. They were used in large strain consolidation numerical analyses of storage ponds to predict water release rates and changes to surface elevations that impact storage volumes and elevation of reclamation surfaces.展开更多
In this paper, the hydro-mechanical behavior and physical properties of mature fine tailings(MFT) under atmospheric drying are investigated through a column study. In the study, evaporation takes place in the developm...In this paper, the hydro-mechanical behavior and physical properties of mature fine tailings(MFT) under atmospheric drying are investigated through a column study. In the study, evaporation takes place in the development of suction in the upper parts of the column and increasing suction leads to higher strength in the tailings. After 5 days, the suction in the first lift is around 17 k Pa in the upper part of the column.When a second lift is added, the first lift initially loses strength but over a 30 days' period, the strength is recovered to its prior value and suction in the second lift reaches 500 k Pa. The vane shear strength values show a substantial increase in the strength of the MFT after 30 days under atmospheric drying and drainage. The 90% strength found in the column exceeds the threshold(5 k Pa). The hydraulic-mechanical properties of the deposited tailings are closely coupled due to several mechanisms, such as evaporation,drainage, self-consolidation, suction and crack development. The findings of this study will provide a better understanding of the placement behavior of multiple lifts of MFT and thus contribute to reclamation design standards and reduce the use of dedicated disposal areas.展开更多
A self-developed ASP agent was used to separate bitumen from Indonesia's oil sands by its comprehensive effect and the separation condition was well investigated. The bitumen extraction conditions for industrial a...A self-developed ASP agent was used to separate bitumen from Indonesia's oil sands by its comprehensive effect and the separation condition was well investigated. The bitumen extraction conditions for industrial application were recommended to cover a mixing temperature of 80℃, a mixing time of 40 min, a mass ratio of ASP agent to oil sands of 4:10, and a floating time of 10 min. Under the above conditions, the bitumen recovery was about 86% and the residual bitumen content in tailings was about 6%. The relationship between the residual bitumen content and the particle size of tailings was studied in order to find the way to reducing the residual bitumen content in tailings. The results showed that the residual bitumen content in tailings decreased with a decreasing tailings particle size. After being milled for 30 min with a mortar, the tailings was reprocessed via extraction by means of the ASP agent, and the residual bitumen content in tailings decreased from 5.47% to 1.25%, which could comply with the disposal requirements.展开更多
基金Project(2006BAB02A03) supported by National Key Technology Research and Development ProgramProject(2006BA02B05) supported by Key Programs for Science and Technology Development of China during the 11th Five Year
文摘A new technology characterized by rapidly non-mechanical settlement of unclassified tailings was developed based on a large number of tests, and dynamic settlement and continual slurry preparation without hardening in vertical sand silo were eventually realized by the addition of an effective flocculating agent (NPA). The results show that the sedimentation velocity of interface between unclassified tailings and water after the addition of NPA increases by 10-20 times, the sedimentation mass fraction of unclassified tailings at the bottom of vertical sand silo is up to 64%, the solid particle content of waste water meets the national standard, and the side influences of NPA can be removed by the addition of fly ash. The industrial test result shows that the system, the addition manner and the equipments are rational, and the vertical sand silo is used efficiently. This developed system is simple with large throughput, and the processing cost is 2.2 yuan(RMB)/m3, only 10%-20% of that by mechanical settlement.
文摘Vast amounts of tailings are produced daily in bitumen extraction from the Athabasca oil sands. The coarse sand from the tailings stream is used to build dykes around the containment basin. The run off slurry arrives at the water’s edge in the tailings pond at a solids concentration of about 3%～8% by mass. Settling of the solids takes place "relatively fast", over several days, creating a "free water zone" that contains little solids. When the fine mineral solids concentration has reached about 15% by mass, the suspension develops non Newtonian properties. After 2～3 years, the suspension concentration reaches a value of about 30% by mass at which the settling rate becomes extremely slow. Methods to handle the already created tailings ponds and new approaches to eliminate the creation of new ones will be discussed both from the industrial and fundamental prospective.
文摘The objectives of this experiment were to evaluate the performance of different plant species growing in different kinds of oil sands fine tailings,and to estimate the uptake of organic contaminants by plants from the oil sands fine tailings.In general,total hydrocarbon in the plant could be ranked(beginning with the highest)as:unweathered plant 4 tailings (UWT),Freeze Thawtailings(FT),weathered plant 4 tailings(WT),and consolidated tailings(CT) for the willow,poplar and cattails.For grass,CT amended with tailings sand and muskeg had the highest hydrocarbon level in the field treatment,however,other three kinds of tailings(FT,WT and UWT) had lower but similar to each other hydrocarbon levels.
文摘In the oil sands industry, high temperature with the addition of a caustic dispersing agent has formed the basis of the Clark hot water extraction process used successfully on a commercial scale to recover bitumen from surface mined oil sands ore since 1967. Processes different from the established Clark process （high temperature and caustic） have been developed to work at a range of temperatures with or without the use of sodium hydroxide. Large scale bitumen extraction pilot tests were performed with two different extraction processes and large strain consolidation tests were performed on the resulting different railings. These consolidation tests determined the compressibility and hydraulic conductivity relationships with void ratio which are engineering properties that influence the long-term disposal of the fine tailings. They were used in large strain consolidation numerical analyses of storage ponds to predict water release rates and changes to surface elevations that impact storage volumes and elevation of reclamation surfaces.
基金the University of Ottawa and the National Natural Sciences and Engineering Research Council of Canada(NSERC)for supporting this research
文摘In this paper, the hydro-mechanical behavior and physical properties of mature fine tailings(MFT) under atmospheric drying are investigated through a column study. In the study, evaporation takes place in the development of suction in the upper parts of the column and increasing suction leads to higher strength in the tailings. After 5 days, the suction in the first lift is around 17 k Pa in the upper part of the column.When a second lift is added, the first lift initially loses strength but over a 30 days' period, the strength is recovered to its prior value and suction in the second lift reaches 500 k Pa. The vane shear strength values show a substantial increase in the strength of the MFT after 30 days under atmospheric drying and drainage. The 90% strength found in the column exceeds the threshold(5 k Pa). The hydraulic-mechanical properties of the deposited tailings are closely coupled due to several mechanisms, such as evaporation,drainage, self-consolidation, suction and crack development. The findings of this study will provide a better understanding of the placement behavior of multiple lifts of MFT and thus contribute to reclamation design standards and reduce the use of dedicated disposal areas.
文摘A self-developed ASP agent was used to separate bitumen from Indonesia's oil sands by its comprehensive effect and the separation condition was well investigated. The bitumen extraction conditions for industrial application were recommended to cover a mixing temperature of 80℃, a mixing time of 40 min, a mass ratio of ASP agent to oil sands of 4:10, and a floating time of 10 min. Under the above conditions, the bitumen recovery was about 86% and the residual bitumen content in tailings was about 6%. The relationship between the residual bitumen content and the particle size of tailings was studied in order to find the way to reducing the residual bitumen content in tailings. The results showed that the residual bitumen content in tailings decreased with a decreasing tailings particle size. After being milled for 30 min with a mortar, the tailings was reprocessed via extraction by means of the ASP agent, and the residual bitumen content in tailings decreased from 5.47% to 1.25%, which could comply with the disposal requirements.
