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Publications (10 of 18) Show all publications
Jia, Q. & Laue, J. (2018). Direct Simple Shear Tests on Swedish Tailings. In: Proceedings of China-Europe Conference on Geotechnical Engineering: . Paper presented at China-Europe Conference on Geotechnical Engineering, Vienna, Austria, August 13-16 2018 (pp. 538-541). Cham: Springer, 1
Open this publication in new window or tab >>Direct Simple Shear Tests on Swedish Tailings
2018 (English)In: Proceedings of China-Europe Conference on Geotechnical Engineering, Cham: Springer, 2018, Vol. 1, p. 538-541Conference paper, Published paper (Refereed)
Abstract [en]

Tailings is a waste stream produced by mining industry. It is often stored on the surface in a retaining structure, called tailing impoundment surrounded by tailing dams. Strength property of tailings is important for safety of tailings dam construction. In this study, direct simple shear tests were performed on two Swedish tailings from Malmberget mine and Svappaavare mine in Northern Sweden. The apparatus used is NGI direct simple shear apparatus. The estimated maximal friction angle from shear tests ranged from 15.9 to 24.3°, with cohesions from 0‐16.3 kPa. One phenomenon noticed was that for tailings the sample height started decrease after dilatancy. In order to know whether this is a material property, or it is due to the defect of the simple shear apparatus, a series of shear tests were done on Kalix sand. The result showed that this phenomenon happened also to the densely compacted sand, though more rarely. The decreased sample height after reaching the peak values is assumed to be related to both particle breakage and the deficiency of the shear apparatus.

Place, publisher, year, edition, pages
Cham: Springer, 2018
Series
Springer Series in Geomechanics and Geoengineering, ISSN 1866-8755
National Category
Geotechnical Engineering
Research subject
Soil Mechanics
Identifiers
urn:nbn:se:ltu:diva-70309 (URN)10.1007/978-3-319-97112-4_120 (DOI)978-3-319-97111-7 (ISBN)978-3-319-97112-4 (ISBN)
Conference
China-Europe Conference on Geotechnical Engineering, Vienna, Austria, August 13-16 2018
Available from: 2018-08-09 Created: 2018-08-09 Last updated: 2018-08-09Bibliographically approved
Zhang, J., Guo, L., Sun, X., Li, W. & Jia, Q. (2018). Study on the Strength Development of Cemented Backfill Body from Lead-Zinc Mine Tailings with Sulphide. Advances in Materials Science and Engineering, 2018, Article ID 7278014.
Open this publication in new window or tab >>Study on the Strength Development of Cemented Backfill Body from Lead-Zinc Mine Tailings with Sulphide
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2018 (English)In: Advances in Materials Science and Engineering, ISSN 1687-8434, E-ISSN 1687-8442, Vol. 2018, article id 7278014Article in journal (Refereed) Published
Abstract [en]

The unconfined compressive strength (UCS) development of cemented backfill materials for lead-zinc mine tailings with sulphide was studied. The results showed that the UCS of the cemented backfill body with ordinary Portland cement (OPC) as binder decreased in the later curing days, regardless of particle size. Under the same conditions, the higher the OPC content, the higher the UCS of the cemented backfill body, and the UCS of the cemented backfill body began to decrease at the longer curing days. Under the same conditions, the finer the tailings, the lower the UCS of the cemented backfill body at each age, and the UCS of the cemented backfill body began to decrease at the earlier curing age. X-ray diffraction analysis (XRD) showed that the reduction of the UCS of the cemented backfill body was related to the formation of an expansive substance (expansive gypsum) in the cemented backfill body, which led to the cracking of the test sample. In the cemented backfill materials of coarse tailings of lead-zinc mine, the composite binder formed by OPC and calcined kaolin (CK) containing metakaolin was used; the amount of calcium hydroxide, the hydration product of cement, was reduced or eliminated due to the pozzolanic reaction of metakaolin; and the amount of expansive gypsum was reduced or eliminated, so the UCS of the cemented backfill body increased within 360 days of curing.

Place, publisher, year, edition, pages
Hindawi Publishing Corporation, 2018
National Category
Geotechnical Engineering
Research subject
Soil Mechanics
Identifiers
urn:nbn:se:ltu:diva-68569 (URN)10.1155/2018/7278014 (DOI)000431299000001 ()2-s2.0-85048731901 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-05-02 (andbra)

Available from: 2018-05-02 Created: 2018-05-02 Last updated: 2018-06-28Bibliographically approved
Guo, L., Peng, X., Yang, X., Shi, C., Yu, B., Xu, W., . . . Jia, Q. (2017). Industrial practice on optimizing tailings composition combined with ore concentration processes. In: 12th International Conference on Mining with Backfill 2017, Minefill 2017: . Paper presented at 12th International Conference on Mining with Backfill 2017, Minefill 2017, Denver, United States 19-22 February 2017 (pp. 69-79). Englewood, CO: Society for Mining, Metallurgy and Exploration
Open this publication in new window or tab >>Industrial practice on optimizing tailings composition combined with ore concentration processes
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2017 (English)In: 12th International Conference on Mining with Backfill 2017, Minefill 2017, Englewood, CO: Society for Mining, Metallurgy and Exploration , 2017, p. 69-79Conference paper, Published paper (Refereed)
Abstract [en]

Cemented paste backfill (CPB) is increasingly applied in underground mines world-wide and has a broad prospect considering its benefits in environmental protection and ground control. During the paste production, a well-graded aggregate is critical for the achievement of CPB. Mine tailings from the outcome of ore-dressing plant are commonly used as the fill aggregate. However, it is difficult to obtain an ideal particle size distribution for the mine tailings which are roughly mixed with final residuum in ore concentration processes. In this study, a novel industrial method is proposed to select fill aggregates from different parts of ore-dressing processes. With combined design of concentration plant and backfill plant, the tailings with desired particle sizes and proportions during the mineral processing are chosen to produce CPB without disturbing the regular ore concentration. The problem of passively accepting final tailings from ore-dressing plant has been improved

Place, publisher, year, edition, pages
Englewood, CO: Society for Mining, Metallurgy and Exploration, 2017
National Category
Geotechnical Engineering
Research subject
Soil Mechanics
Identifiers
urn:nbn:se:ltu:diva-63541 (URN)9781510835818 (ISBN)
Conference
12th International Conference on Mining with Backfill 2017, Minefill 2017, Denver, United States 19-22 February 2017
Available from: 2017-05-26 Created: 2017-05-26 Last updated: 2018-05-28Bibliographically approved
Jia, Q., Yang, Q., Guo, L., Knutsson, S., Xue, P., Liu, G. & Jiang, L. (2016). Effects of fine content, binder type and porosity on mechanical properties of cemented paste backfill with co-deposition of tailings sand and smelter slag. The Electronic journal of geotechnical engineering, 21(20), 6971-6988
Open this publication in new window or tab >>Effects of fine content, binder type and porosity on mechanical properties of cemented paste backfill with co-deposition of tailings sand and smelter slag
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2016 (English)In: The Electronic journal of geotechnical engineering, ISSN 1089-3032, E-ISSN 1089-3032, Vol. 21, no 20, p. 6971-6988Article in journal (Refereed) Published
Abstract [en]

Mine backfilling is a process where the underground voids resulted from mining are filled with waste materials. The potential of co-depositing iron sand produced from smelting process with tailings sand was investigated in the present study. Different amounts of iron sand were mixed with the tailings sand to prepare cemented paste backfill (CPB) samples. Two types of binders were used. Uniaxial compression tests were performed for the CPB samples after 28 days of curing. The porosities of the samplers after curing were calculated to correlate the porosity with the uniaxial compression strength, UCS. Results from uniaxial compression tests showed that the amount of iron sand and the type of the binder influences the UCS, as well as content values of fines and porosity. These results demonstrated the possibility for a part of Fe-sand to be deposited together with the tailings sand to increase UCS values for the CPB samples, which will be beneficial for both mining operation and environmental protection.

Place, publisher, year, edition, pages
Mete Öner, 2016
National Category
Geotechnical Engineering Metallurgy and Metallic Materials
Research subject
Soil Mechanics; Process Metallurgy
Identifiers
urn:nbn:se:ltu:diva-60393 (URN)2-s2.0-84992520613 (Scopus ID)
Note

Validerad; 2016; Nivå 1; 2016-11-14 (andbra)

Available from: 2016-11-14 Created: 2016-11-14 Last updated: 2018-11-23Bibliographically approved
Ekström, I., Ljunggren, M., Andersson, C. A., Jia, Q. & Laue, J. (2016). Large-scale shear box tests to determine rockfill parameters. In: Association of State Dam Safety Officials Annual Conference 2016: Dam Safety 2016. Paper presented at Association of State Dam Safety Officials Annual Conference 2016, Dam Safety 2016, Philadelphia, United States, 11-14 September 2016 (pp. 828-845). Lexington, Kentucky: Association of State Dam Safety Officials, 2
Open this publication in new window or tab >>Large-scale shear box tests to determine rockfill parameters
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2016 (English)In: Association of State Dam Safety Officials Annual Conference 2016: Dam Safety 2016, Lexington, Kentucky: Association of State Dam Safety Officials , 2016, Vol. 2, p. 828-845Conference paper, Published paper (Refereed)
Abstract [en]

A 160 (525 ft) m high asphalt concrete core rockfill dam is developed in an area of very high seismicity in Cetin, Turkey. Topographical constraints of the dam footprint impose a steep outer geometry of the dam, requiring the geotechnical properties of the rockfill to comply with certain minimum limits. Test blasting in a potential quarry and rockfill rolling compaction trials suggest that the tested gneiss/schist rock material to a large extent is weathered and weak. The friction angle of the rockfill is a decisive parameter for both the static and dynamic stability of the dam slopes and especially for the deformation of the dam crest due to strong earthquakes. The suggested rock fill material has therefore undergone detailed testing. To this end, large-scale shear tests with a 1000 mm diameter sample cylinder have been carried out at the Luleå Technical University in Sweden.

Place, publisher, year, edition, pages
Lexington, Kentucky: Association of State Dam Safety Officials, 2016
National Category
Geotechnical Engineering
Research subject
Soil Mechanics
Identifiers
urn:nbn:se:ltu:diva-65084 (URN)2-s2.0-85026344581 (Scopus ID)9781510830752 (ISBN)
Conference
Association of State Dam Safety Officials Annual Conference 2016, Dam Safety 2016, Philadelphia, United States, 11-14 September 2016
Available from: 2017-08-15 Created: 2017-08-15 Last updated: 2018-05-28Bibliographically approved
Jia, Q. (2015). Estimation of industrial dust using exposure-profiling method (ed.). (Doctoral dissertation). Paper presented at . Luleå tekniska universitet
Open this publication in new window or tab >>Estimation of industrial dust using exposure-profiling method
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Dust is a primary cause for air quality deterioration, as well as a potential health hazard. Mining and construction sites, in particular, are the most profound in dust generation. The possible source activities are drilling, loading, transporting, dumping, crushing, stockpiles, waste rock and unprotected open surfaces, etc. Dust can be any airborne contaminants occur in the gaseous form or as aerosols. This research dealt with ‘fugitive dust’ which is defined as dust that could not reasonably pass through a stack, chimney, vent, or other functionally equivalent openings, and does not include non-geologic particulate matter emitted directly by internal and external combustion processes. Fugitive dust and dust are used interchangeably in this thesis.In mining areas, construction sites or other industrial areas, fugitive dust is generated through wind erosion of surface materials or application of mechanical forces. The transportation of dust particles is a result of wind direction, velocity, source activities, particles dispersion characteristics, topography, control methods, and so on. A case study on dust fallout from Malmberget Iron Mine showed that the dust generation due to the mining activities in Malmberget Iron Mine influences the down-wind residential areas depending on the weather conditions and the rate of dust generation; the sources of dust generation from Malmberget Iron Mine are haul road transportations, active stockpiles, and the open pit with the loose surface materials. Dust due to wind erosion of the loose material from the open pit is somewhat insignificant as the lab tests showed that the surface material was slightly to moderately erodible and has the soil erosion index of 4.7kg/m2/year.To measure dust generation, three sites were used. They are unpaved roads, road construction and the Aitik tailings dam. This was achieved using an exposure-profiling method with Big Spring Number Eight (BSNE) samplers. Wind erosion prediction system (WEPS) was also used to model the wind erosion process on the Aitik tailings dam. The measurement for the unpaved roads showed that dust generation strongly depends on the driving speed and silt content of road surface materials when the moisture contents are the same. The estimated dust emission rate from the road construction work during the measuring period was 22.87 kg TSP/d, of which 6 kg/d was from construction work and 16.87 kg/d was generated due to traffic on temporary roads. The measured total suspended material from the Aitik tailings dam was 0.475kg/m2 for five days, which had a big difference with simulated value of 4.4559 kg/m2. Many reasons contributed to the disagreement between the simulated value and the measured value. In order to use the model for mining industry more tests are required to validate the modeling result. This could be useful in adjusting the internal coefficients and empirical equations.The research concluded that the exposure-profiling method with BSNEs worked best for the unpaved roads which is a line source, whereas for the road construction and the Aitik tailings dam the method was not robust enough. BSNE sampler is cheap and widely used, but can produce poor accuracy in some cases. Upwind-downwind method with active samplers is recommended for the road construction and the tailings dam which are the non-line sources in the future work. Both of the methods are applicable for development of dust emission factors. WESP is a soil erosion model designed for agriculture land and need to be validated with more field tests in order to be used for the tailings dam.

Place, publisher, year, edition, pages
Luleå tekniska universitet, 2015
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
National Category
Geotechnical Engineering
Research subject
Soil Mechanics
Identifiers
urn:nbn:se:ltu:diva-18651 (URN)99941cd4-82c2-48d9-b1e4-85c72862b85f (Local ID)978-91-7583-194-7 (ISBN)978-91-7583-195-4 (ISBN)99941cd4-82c2-48d9-b1e4-85c72862b85f (Archive number)99941cd4-82c2-48d9-b1e4-85c72862b85f (OAI)
Note

Godkänd; 2015; 20140506 (qijia); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Qi Jia Ämne: Geoteknik/Soil Mechanics and Foundation Engineering Avhandling: Estimation of Industrial Dust Using Exposure-Profiling Method Opponent: Professor emeritus John McManus, School of Geography and Geosciences, University of St Andrews, St Andrews, Storbritannien Ordförande: Professor Sven Knutsson, Avd för geoteknologi, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet, Luleå Tid: Onsdag 23 september 2015, kl 10.00 Plats: F1031, Luleå tekniska universitet

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-05-28Bibliographically approved
Jia, Q., Al-Ansari, N. & Knutsson, S. (2014). Modeling of wind erosion of the Aitik tailings dam using SWEEP model (ed.). Paper presented at . Engineering, 6(7), 355-364
Open this publication in new window or tab >>Modeling of wind erosion of the Aitik tailings dam using SWEEP model
2014 (English)In: Engineering, ISSN 1947-3931, E-ISSN 1947-394X, Vol. 6, no 7, p. 355-364Article in journal (Refereed) Published
Abstract [en]

Waste impoundments are usually not protected by any growing crops, soil roughness, or wind barriers, and dust due to wind erosion of the surface waste material can be a major environmental problem. The tailings dam in Aitik is highly susceptible to wind erosion when it is dry and windy. Strong dust storms may occur during dry seasons. These events are short-lived but may transport a huge amount of particulate matter and adversely impact air quality in downwind areas. This study estimated material loss from the Aitik tailings dam using SWEEP model. The simulated total material loss, saltation and creep loss, suspension loss and PM10 loss were 4.4941kg/m2, 0.042 kg/m2, 4.4559 kg/m2, 0.264057 kg/m2 respectively. To control the dust generation wind breaks could be suggested to be installed at 800m downwind the upwind edge of the tailings dam to reduce the saltation and creep and it would in turn reduce suspended emission. The measured total suspended material for five days by exposure profiling method was 0.475kg/m2, which had a big difference with simulate a value of 4.4559 kg/m2. Many reasons contributed to the disagreement of simulated value and measured value in this study. In order to use the model for mining industry more tests are needed to validate the modeling result and calibration methods could be useful in adjusting the internal coefficients and empirical equations.

National Category
Geotechnical Engineering
Research subject
Soil Mechanics
Identifiers
urn:nbn:se:ltu:diva-13600 (URN)10.4236/eng.2014.67038 (DOI)cd645531-98e6-4fa9-b386-fa2d46fd3db5 (Local ID)cd645531-98e6-4fa9-b386-fa2d46fd3db5 (Archive number)cd645531-98e6-4fa9-b386-fa2d46fd3db5 (OAI)
Note
Validerad; 2014; 20140304 (nadhir)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-05-28Bibliographically approved
Jia, Q., Al-Ansari, N. & Knutsson, S. (2013). Dust emission from unpaved roads in Luleå, Sweden (ed.). Journal of Earth Sciences and Geotechnical Engineering, 3(1), 1-13
Open this publication in new window or tab >>Dust emission from unpaved roads in Luleå, Sweden
2013 (English)In: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 3, no 1, p. 1-13Article in journal (Refereed) Published
Abstract [en]

The dust emission from unpaved roads, if not controlled, can cause enormous problems. Though a few real-world measurements of road dust have been done by automated samplers in Sweden, measurement by BSNE (Big Spring Number Eight) and the estimation of total dust generation from vehicle driving is rare. This study measured and analyzed dust emission by BSNE at two unpaved roads in Luleå, Sweden, at the driving speed of 20, 30, 40, and 50 km/h different heights. Even though US EPA excluded vehicle speed as a parameter in estimating dust emission factors for unpaved roads, this study confirmed a strong dependence of dust emission on vehicle speed. This is in agreement with several recent studies which concluded dust emission increases with driving speed exponentially or linearly, however the power law is the best description for the data from this study. The comparison with estimated dust emission by US EPA’s equation showed the equation underestimates the dust emission more than 50 percent when vehicle speed and silt content is higher than 25.40km/h and 2.17 percent respectively. There might be some interrelationship between driving speed and silt content in road surface.Earlier researchers have reported increased dust emission with increasing silt content and this is confirmed by this study.

Place, publisher, year, edition, pages
Scienpress Ltd, 2013
National Category
Geotechnical Engineering
Research subject
Soil Mechanics
Identifiers
urn:nbn:se:ltu:diva-12239 (URN)b571aaf1-4287-465a-9261-7aac833f1234 (Local ID)b571aaf1-4287-465a-9261-7aac833f1234 (Archive number)b571aaf1-4287-465a-9261-7aac833f1234 (OAI)
Note

Validerad; 2013; 20130212 (nadhir)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-12-14Bibliographically approved
Jia, Q., Huang, Y., Al-Ansari, N. & Knutsson, S. (2013). Dust emissions from landfill deposition: a case study in Malmberget mine,Sweden (ed.). Journal of Earth Sciences and Geotechnical Engineering, 3(3), 25-34
Open this publication in new window or tab >>Dust emissions from landfill deposition: a case study in Malmberget mine,Sweden
2013 (English)In: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 3, no 3, p. 25-34Article in journal (Refereed) Published
Abstract [en]

A great amount of industrial wastes are produced in Sweden every year. In 2008 there were 97.9 million tons of wasted generated, among which 93 million tons industrial waste were produced. 64.1% of industrial wastes were deposited in the landfill sites. Dust generation is one of the most important problems associated with industrial waste and landfills. The particulate dust emissions come from the industrial waste may contain heavy metal and produce environmental problems and potential health risks. Active and passive samplers, deposition pans are common equipment to collect dust samples. Real-time monitors use laser diffraction to recording continuous dust concentration. Dust emission from Malmberget mine in Sweden was analyzed as a case study. Dust was collected by NILU deposit gauge from 26 stations. Generally speaking the amount of dust fallout was decreasing with time because of implemented dust control methods. During the period August 2009 to August 2010, among all the measuring stations through the year, the maximum and the minimum value were 1284 g/100m2/30d and 9 g/100m2/30d. Two sources of dust generation were identified. The first was located close to the open pit, and the second near the current mining industrial center. The dust generation due to road construction was calculated.

Place, publisher, year, edition, pages
Scienpress Ltd, 2013
National Category
Geotechnical Engineering
Research subject
Soil Mechanics
Identifiers
urn:nbn:se:ltu:diva-12220 (URN)b505f968-ab9e-40ab-ac4f-0a2058763871 (Local ID)b505f968-ab9e-40ab-ac4f-0a2058763871 (Archive number)b505f968-ab9e-40ab-ac4f-0a2058763871 (OAI)
Note

Validerad; 2013; 20130717 (nadhir)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-12-14Bibliographically approved
Jia, Q., Al-Ansari, N. & Knutsson, S. (2013). Estimation of road dust using BSNEs (ed.). Paper presented at . Natural Science, 5(5), 567-572
Open this publication in new window or tab >>Estimation of road dust using BSNEs
2013 (English)In: Natural Science, ISSN 2150-4091, E-ISSN 2150-4105, Vol. 5, no 5, p. 567-572Article in journal (Refereed) Published
Abstract [en]

Mining is a core industry in Sweden and plays an important role in the economic development of the country. Though the importance of mining dust has been well recognized, the quantification of dust production with regard to individual source activity has rarely been done in Sweden. Depending on the type of source activity, dust estimation method can be chosen from three alternatives: exposure profiling methods, back calculation method, and wind erosion prediction method. Also included in the paper is an example of experiment, which was executed on two unpaved roads in Lulea, Sweden by using exposure profiling method. The experiment concluded that dust emission due to vehicle transportation is strongly dependent on traveling speed and road bed material.

National Category
Geotechnical Engineering
Research subject
Soil Mechanics
Identifiers
urn:nbn:se:ltu:diva-5667 (URN)10.4236/ns.2013.55072 (DOI)3d471f32-b0f8-44e6-9562-f37557b0bea3 (Local ID)3d471f32-b0f8-44e6-9562-f37557b0bea3 (Archive number)3d471f32-b0f8-44e6-9562-f37557b0bea3 (OAI)
Note
Godkänd; 2013; 20130403 (nadhir)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-05-28Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-2631-3502

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