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Jia, Y., Hamberg, R., Qureshi, A., Mäkitalo, M. & Maurice, C. (2019). Variation of green liquor dregs from different pulp and paper mills for use in mine waste remediation. Environmental science and pollution research international, 26(30), 31284-31300
Open this publication in new window or tab >>Variation of green liquor dregs from different pulp and paper mills for use in mine waste remediation
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2019 (English)In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 26, no 30, p. 31284-31300Article in journal (Refereed) Published
Abstract [en]

The geotechnical, chemical, and mineralogical properties of green liquor dregs (GLDs) generated as byproducts from five paper mills were investigated to assess their buffering and heavy metal immobilization capacities and their roles as water and oxygen barriers. One type of GLD was further studied to test the effects of the retrieval process and the storage, drying, and hydration of GLD. The high water retention capacity of the GLDs is valuable for limiting O2diffusion. Laboratory results showed that the GLDs had hydraulic conductivities of 3.7 × 10−9–4.6 × 10−8 m/s and varied regularly in plasticity. The chemical and mineralogical compositions of the GLDs varied greatly, reflecting the raw material used to produce paper and the process used to retrieve GLDs. Although they had high total heavy metal contents, none of the leached elements from the GLDs (L/S 10 cm3/kg) exceeded the European Union’s limits for landfills of non-hazardous waste. The GLDs exhibited high buffering capacities. In a supplementary test, the buffering capacities varied (0.0041–0.0114 M H+/g GLD) over 72 d after acid was added to the GLD. Changing the filtration process did not greatly affect the GLDs’ properties but mainly affected the hydraulic conductivity, total heavy metal contents and sulfur content. Analyzing the storage of GLDs is necessary in the mining industry because remediation measures require large amounts of material over short periods. The buffering capacity of the dried GLD decreased slightly. The effect of dewatering caused by the mixing of 2% Na-lignosulfate with GLD (w/w) was low.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Acid neutralization, Buffering capacity, Heavy metals, Water retention, Plasticity, Beneficiation
National Category
Geotechnical Engineering Geochemistry
Research subject
Applied Geochemistry; Soil Mechanics
Identifiers
urn:nbn:se:ltu:diva-75826 (URN)10.1007/s11356-019-06180-0 (DOI)000494047900065 ()31471848 (PubMedID)
Note

Validerad;2019;Nivå 2;2019-11-22 (johcin)

Available from: 2019-09-03 Created: 2019-09-03 Last updated: 2019-11-22Bibliographically approved
Hamberg, R. (2018). Cementation of cyanidation tailings – effects on the release of As, Cu, Ni and Zn. (Doctoral dissertation). Luleå: Luleå University of Technology
Open this publication in new window or tab >>Cementation of cyanidation tailings – effects on the release of As, Cu, Ni and Zn
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Alternative title[sv]
Solidifiering av anrikningssand från cyanidlakning – effekter på lakning av arsenik, nickel, zink och koppar
Abstract [en]

Knowledge about mineralogy and chemical composition in sulfidic tailings is essential to predict how tailings management may affect the future leachate quality. At a gold mine in the north of Sweden, gold was extracted from inclusions in arsenopyrite and pyrrhotite by the use of cyanide. Sulfides in the ore dissolved to a large extent during the cyanide leaching process causing sulfide-related elements such as As, Cu, Ni and Zn to be mobilized to a various extent. In a subsequent water treatment process, a significant proportion of As and Cu was captured in secondary formed Fe-precipitates. Large proportions of water-soluble Ni- and Zn-species in tailings suggested that this treatment was insufficient to reduce the mobility of Ni and Zn. Maintaining oxidized, neutral conditions is of major importance for the immobility of As, Cu, Ni and Zn during further management of the cyanidation tailings (CT).

Part of the CT were planned to be managed in underground cavities by the use of a cemented paste backfill (CPB) -application. In CPB, a monolithic mass is formed as tailings are mixed with small proportions (4-7 weight %) of pozzolanic materials and backfilled into underground excavated areas. Using a CPB-application may decrease the sulphide oxidation rate, reducing exposure of mineral surfaces to oxygen and increasing water saturation levels within the material. In this study, CT was mixed with binders (1-3 wt. %) for the formation of a low-strength (0.2 Mpa) CT-CPB-mass. These mixtures were stored at moisturized conditions and subsequently subjected to oxidized and flooded conditions in a laboratory-based study. During short-term storing, high water saturation levels were preserved in the CT-CPB-mixtures, but, sulfide oxidation still progressed, and the release of Zn, Cu, and Ni was still lower compared to that in CT. The opposite was true for As, probably due to a desorption from Fe-precipitates. The desorbed As was subsequently incorporated into less acid-tolerant species (i.e. Ca-arsenates and As bonded to cementitious phases) in the CT-CPB:s, that readily dissolved and released more As compared to that in CT.

A complete flooding of CPB-filled workings may take a long time to be reached. During this transition period, zones with low levels of water saturation forms in the CPB-monoliths, which could increase the sulphide oxidation rate, lower pH and dissolve the cementitious binders. In this study, strength decreased along with the water saturation levels in the CPB-mixtures, due to a more extensive pyrrhotite oxidation. A minimal proportion (1 wt. %) of binders did not suppress Cu and As leaching during flooding, but Ni and Zn-leaching were still lower than from CT. In the CT-CPB:s, proportions of As, Cu, Ni and Zn associated with cementitious phases increased in tandem with the fraction of binders. Using higher binder proportions in the CPB, as water saturation levels were lowered, substantially increased the Zn-release while there was an insignificant change in the As-release, and substantially lower Cu- and Ni-release. Pyrrhotite oxidation proceeded in the CT-CPB-mixtures independent of water saturation level. So, increasing binder proportion in a CPB does not necessary mean that trace metals are more stabilized, due to the formation of acid-intolerant fractions. Results from this study, pinpoints the importance of having knowledge about trace element distribution and mineral assemblage in tailings before management methods are chosen and implemented.

Place, publisher, year, edition, pages
Luleå: Luleå University of Technology, 2018. p. 35
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
National Category
Geochemistry
Research subject
Applied Geochemistry
Identifiers
urn:nbn:se:ltu:diva-68436 (URN)978-91-7790-124-2 (ISBN)978-91-7790-125-9 (ISBN)
Public defence
2018-06-15, E246, Luleå, 09:00 (Swedish)
Opponent
Supervisors
Available from: 2018-04-23 Created: 2018-04-20 Last updated: 2019-11-22Bibliographically approved
Hamberg, R., Maurice, C. & Alakangas, L. (2018). The formation of unsaturated zones within cemented paste backfill mixtures: Effects on the release of copper, nickel, and zinc. Environmental science and pollution research international, 25(21), 20809-20822
Open this publication in new window or tab >>The formation of unsaturated zones within cemented paste backfill mixtures: Effects on the release of copper, nickel, and zinc
2018 (English)In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 25, no 21, p. 20809-20822Article in journal (Refereed) Published
Abstract [en]

Flooding of cemented paste backfill (CPB) filled mine workings is, commonly, a slow process and could lead to the formation of unsaturated zones within the CPB-fillings. This facilitates the oxidation of sulfide minerals, and thereby increases the risk of trace-metal leaching. Pyrrhotitic tailings from a gold mine (CT), containing elevated concentrations of Ni, Cu and Zn, were mixed with cement and/or fly ash (1-3 wt. %) to form CT-CPB-mixtures. Pyrrhotite oxidation progressed more extensively during unsaturated conditions, where acidity resulted in dissolution of the Ni, Cu, and Zn associated with amorphous Fe-precipitates and/or cementitious phases. The establishment of acidic, unsaturated conditions in CT-CBP:s with low fractions (1 wt. %) of binders increased the Cu-release (to be higher than that from CT), owing to the dissolution of Cu-associated amorphous Fe-precipitates. In CT-CPB:s with relatively high proportions of binder, acidity from pyrrhotite oxidation was buffered to a greater extent. At this stage, Zn-leaching increased due the occurrence of fly ash-specific Zn-species soluble in alkaline conditions. Irrespective of binder proportion and water saturation level, the Ni- and Zn-release were lower, compared to that in CT. Fractions of Ni, Zn, and Cu associated with acid-soluble phases or amorphous Fe-precipitates, susceptible to remobilization under acidic conditions, increased in tandem with binder fractions. Pyrrhotite oxidation occurred irrespective of the water saturation level in the CPB-mixtures. That in turn, poses an environmental risk, whereas a substantial proportion of Ni, Cu and Zn were associated with acid-soluble phases.

Place, publisher, year, edition, pages
Springer, 2018
Keywords
Tailings management, cement, trace metal leaching
National Category
Earth and Related Environmental Sciences Geochemistry
Research subject
Applied Geochemistry
Identifiers
urn:nbn:se:ltu:diva-68435 (URN)10.1007/s11356-018-2222-9 (DOI)000438830900052 ()29756187 (PubMedID)
Note

Validerad;2018;Nivå 2;2018-08-07 (andbra)

Available from: 2018-04-20 Created: 2018-04-20 Last updated: 2019-11-22Bibliographically approved
Hamberg, R., Maurice, C. & Alakangas, L. (2017). Lowering the water saturation level in cemented paste backfill mixtures: Effect on the release of arsenic. Minerals Engineering, 112, 84-91
Open this publication in new window or tab >>Lowering the water saturation level in cemented paste backfill mixtures: Effect on the release of arsenic
2017 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 112, p. 84-91Article in journal (Refereed) Published
Abstract [en]

The Cemented Paste Backfill (CPB) method allows the mixing of dewatered tailings slurries with cementitious binders to backfill excavated underground workings. After mine closure, CPB workings are permanently flooded by rising groundwater. This flooding is considered beneficial for reducing the risk of acid generation associated with CPB containing sulphide minerals. In general, CPB workings are slowly flooded and the process may lead to regions with a low degree of water saturation to form within the CPB. This in turn, may increase oxygen ingress in the CPB, thereby prolonging oxidation of the minerals. To investigate the environmental impact of this oxidation, tailings containing elevated concentrations of arsenic (As) and pyrrhotite were handled via CPB. In this study, CPB mixtures containing 1–3 wt.% of cementitious binders and tailings was studied. The water saturation level in the CPB-mixtures was lowered as curing time extended. In mimicked flooded conditions, the mobility of As in the CPB mixtures was correlated with As-bearing cementitious phases that are sensitive to a reduction in the pH. In CPB-mixtures with lower proportions of binders, cementitious As-phases dissolved while the water saturation level decreased to form more stable As-phases. Increasing binder fractions, most of the cementitious As-phases persisted in the CPB while water saturation levels were lowered and release of As increased. Regardless of curing conditions, managing these tailings via the CPB method yielded increased mobility of As compared with that in the unmodified tailings; this resulted possibly from the formation of less acid-tolerant As species.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Geochemistry
Research subject
Applied Geochemistry
Identifiers
urn:nbn:se:ltu:diva-65077 (URN)10.1016/j.mineng.2017.05.005 (DOI)000410868200011 ()2-s2.0-85026233469 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-08-15 (andbra)

Available from: 2017-08-15 Created: 2017-08-15 Last updated: 2019-11-22Bibliographically approved
Kumpiene, J., Nordmark, D., Hamberg, R., Carabante, I., Simanavičienė, R. & Česlovas Aksamitauskas, V. (2016). Leaching of arsenic, copper and chromium from thermally treated soil. Journal of Environmental Management, 183(3), 460-466
Open this publication in new window or tab >>Leaching of arsenic, copper and chromium from thermally treated soil
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2016 (English)In: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 183, no 3, p. 460-466Article in journal (Refereed) Published
Abstract [en]

Thermal treatment, if properly performed, is an effective way of destroying organic compounds in contaminated soil, while impact on co-present inorganic contaminants varies depending on the element. Leaching of trace elements in thermally treated soil can be altered by co-combusting different types of materials. This study aimed at assessing changes in mobility of As, Cr and Cu in thermally treated soil as affected by addition of industrial by-products prior to soil combustion. Contaminated soil was mixed with either waste of gypsum boards, a steel processing residue (Fe3O4), fly ash from wood and coal combustion or a steel abrasive (96.5% Fe0). The mixes and unamended soil were thermally treated at 800 °C and divided into a fine fraction <0.125 mm and a coarse fraction >0.125 mm to simulate particle separation occurring in thermal treatment plants. The impact of the treatment on element behaviour was assessed by a batch leaching test, X-ray absorption spectroscopy and dispersive X-ray spectrometry. The results suggest that thermal treatment is highly unfavourable for As contaminated soils as it increased both the As leaching in the fine particle size fraction and the mass of the fines (up to 92%). Soil amendment with Fe-containing compounds prior to the thermal treatment reduced As leaching to the levels acceptable for hazardous waste landfills, but only in the coarse fraction, which does not justify the usefulness of such treatment. Among the amendments used, gypsum most effectively reduced leaching of Cr and Cu in thermally treated soil and could be recommended for soils that do not contain As. Fly ash was the least effective amendment as it increased leaching of both Cr and As in majority of samples.

National Category
Other Environmental Engineering
Research subject
Waste Science and Technology
Identifiers
urn:nbn:se:ltu:diva-59700 (URN)10.1016/j.jenvman.2016.08.080 (DOI)000385900000003 ()27612616 (PubMedID)2-s2.0-84992153631 (Scopus ID)
Note

Validerad; 2016; Nivå 2; 2016-10-12 (andbra)

Available from: 2016-10-12 Created: 2016-10-12 Last updated: 2018-07-10Bibliographically approved
Hamberg, R., Bark, G., Maurice, C. & Alakangas, L. (2016). Release of arsenic from cyanidation tailings (ed.). Paper presented at . Minerals Engineering, 93, 57-64
Open this publication in new window or tab >>Release of arsenic from cyanidation tailings
2016 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 93, p. 57-64Article in journal (Refereed) Published
Abstract [en]

At a gold mine in northern Sweden, gold occurring as inclusions in pyrrhotite and arsenopyrite is leached by cyanidation of the ore. The main sulphide minerals in the ore are pyrrhotite and arsenopyrite. Effluents from the cyanidation process are treated with Fe2(SO4)3 to form Fe-precipitates suitable for the co-precipitation of As. The aim of this study was to perform static and kinetic leaching tests on the ore and tailings to define geochemical processes governing As mobility. Sequential leaching tests suggested that the majority of dissolved As deriving from the sulphide fraction in the ore was incorporated in newly formed Fe-precipitates in the tailings. The mobility of As in the tailings was therefore mainly dependent on the stability of these As-bearing Fe-precipitates. Weathering cell tests (WCT) involving 31 weekly cycles of wetting and air exposure were conducted to assess the stability of the As in the tailings under accelerated weathering conditions. The first stage of the WCT was characterized by a pH ≈ 5 and low As leaching, probably driven by the dissolution of amorphous Fe-As species. In the second stage of the WCT, leaching of Fe, S and As increased and the pH decreased to <3.5. An increase of the leachate’s molar Fe/S-ratio suggested that pyrrhotite oxidation was occurring. The falling pH destabilized As-bearing Fe-precipitates, causing further As release. The total As release during the WCT corresponded to only a small proportion of the tailings’ total As content. The accelerated As-leaching observed towards the end of the WCT could thus indicate that its release could increase progressively over time.

National Category
Geochemistry Geology
Research subject
Tillämpad geokemi; Ore Geology
Identifiers
urn:nbn:se:ltu:diva-5851 (URN)10.1016/j.mineng.2016.04.013 (DOI)000377313900008 ()2-s2.0-84964596057 (Scopus ID)409d1fb8-7260-414b-88b4-4904aadd11f9 (Local ID)409d1fb8-7260-414b-88b4-4904aadd11f9 (Archive number)409d1fb8-7260-414b-88b4-4904aadd11f9 (OAI)
Note
Validerad; 2016; Nivå 2; 20160502 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2019-11-22Bibliographically approved
Hamberg, R., Alakangas, L. & Maurice, C. (2016). The release of arsenic from cyanidation tailings. In: Bhattacharya, Prosun; Vahter, Marie; Jarsjo, Jerker; Kumpiene, Jurate; Charlotte, Sparrenbom (Ed.), Arsenic Research and Global Sustainability: Proceedings of the 6th International Congress on Arsenic in the Environment, AS 2016. Paper presented at 6th International Congress on Arsenic in the Environment, AS 2016, Stockholm, 19-23 June 2016 (pp. 201-202). London: CRC Press
Open this publication in new window or tab >>The release of arsenic from cyanidation tailings
2016 (English)In: Arsenic Research and Global Sustainability: Proceedings of the 6th International Congress on Arsenic in the Environment, AS 2016 / [ed] Bhattacharya, Prosun; Vahter, Marie; Jarsjo, Jerker; Kumpiene, Jurate; Charlotte, Sparrenbom, London: CRC Press, 2016, p. 201-202Conference paper, Published paper (Refereed)
Abstract [en]

Tailings from a gold mine containing 1000 mg/kg of As were used to predict the release of As over an extended period of time. Post-cyanide mine processes were aiming to form arsenates and Fe-hydrates for effective As-immobilization. Speciation of the As in ore and tailings samples revealed that mining processes have dissolved the majority of the arsenopyrite in the ore, causing secondary As phases to co-precipitate with newly formed Fe-hydrates. Weathering Cell Tests (WCT) were conducted to assess the effect of weathering on the stability of As in the tailings. As-bearing Fe-hydrates remained intact during the early stages of the WCT. During later stages of the WCT, the release of As, Fe and S increased due to pyrrhotite oxidation and the destabilization of As-bearing Fe-hydrates. Low proportions of As was released in WCT, but additional pyrrhotite oxidation as pH falling to < 3 could further destabilize As-bearing Fe-hydrates

Place, publisher, year, edition, pages
London: CRC Press, 2016
Series
Arsenic in the environment., Proceedings
National Category
Geochemistry
Research subject
Applied Geochemistry
Identifiers
urn:nbn:se:ltu:diva-63073 (URN)2-s2.0-85016963245 (Scopus ID)9781315629438 (ISBN)
Conference
6th International Congress on Arsenic in the Environment, AS 2016, Stockholm, 19-23 June 2016
Available from: 2017-04-19 Created: 2017-04-19 Last updated: 2019-11-22Bibliographically approved
Hamberg, R., Maurice, C. & Alakangas, L. (2015). The use of low binder proportions in cemented paste backfill: Effects on As-leaching (ed.). Paper presented at . Minerals Engineering, 78, 74-82
Open this publication in new window or tab >>The use of low binder proportions in cemented paste backfill: Effects on As-leaching
2015 (English)In: Minerals Engineering, ISSN 0892-6875, E-ISSN 1872-9444, Vol. 78, p. 74-82Article in journal (Refereed) Published
Abstract [en]

Gold is extracted by cyanide leaching from inclusions in arsenopyrite at a mine in the north of Sweden. The major ore mineral assemblage consists of pyrrhotite and arsenopyrite–loellingite. Arsenopyrite is assumed to be oxidized during cyanidation and the stability of secondary As-phases needs to be assessed. One way of managing such tailings is to convert them into a monolithic mass by using a method called cemented paste backfill (CPB). In CPB, tailings are traditionally mixed with water (typically 25% by weight) and small amounts (3–7%) of binders, and backfilled into excavated underground areas. To investigate the release of arsenic (As) from CPB prepared from As-rich tailings, tailings containing approx. 1000 ppm of As, mainly in the form of As-bearing iron (Fe)-precipitates (FEP), were mixed with small quantities (1–3%) of biofuel fly ash (BFA), ordinary cement, and water to produce monolithic CPB masses. CPB-recipes were designed to meet the strength demand of 200 kPa, stated by the mine operators. Tank leaching tests (TLT) and the weathering cell test (WCT) were used to compare the leaching behavior of As in unmodified tailings and CPB-materials. Results from the leaching tests (TLT and WCT) showed that the inclusion of As-rich tailings into a cementitious matrix increased leaching of As. This behavior could partially be explained by an increase of pH where As sorbed to FEPs becomes unstable. In the CPB mixtures, small (>1%) proportions of the total As in the solid material was released from less acid-tolerant species (i.e. Ca-arsenates and As bonded to cementitious phases). Unmodified tailings generated an acidic environment in flooded conditions at which As-bearing FEPs were stable. Acid was added to the crushed CPB materials during later stages of the WCTs to mimic the effects of weathering. This increased the leaching of Fe and had minor effects on that of As but did not affect S-leaching.

National Category
Geochemistry
Research subject
Applied Geology
Identifiers
urn:nbn:se:ltu:diva-14149 (URN)10.1016/j.mineng.2015.04.017 (DOI)000358099500010 ()2-s2.0-84929090904 (Scopus ID)d7bcada2-4c61-4983-9a32-425e0acb55e0 (Local ID)d7bcada2-4c61-4983-9a32-425e0acb55e0 (Archive number)d7bcada2-4c61-4983-9a32-425e0acb55e0 (OAI)
Note
Validerad; 2015; Nivå 2; 20150518 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2019-11-22Bibliographically approved
Hamberg, R. (2014). Characterization and solidification of arsenic-rich cyanided tailings (ed.). (Licentiate dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Characterization and solidification of arsenic-rich cyanided tailings
2014 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Information on the occurrence of As species and iron sulphide minerals in tailings is essential for predicting therelease of As over extended period of time. Tailings originating from a goldmine in northern Sweden with low content of trace elements except for As were used for this purpose. The dominating sulphides were pyrrhotite and arsenopyrite. The samples used in the study were post-cyanided, tailings slurries treated with Fe2(SO4)3 and H2O2 to form arsenates and Fe-hydrates for effective As-immobilization. Speciation of the As in ore and tailings samples revealed that mining processes have dissolved the majority of the arsenopyrite in the ore, causing secondary As phases to co-precipitate with newly formed Fe-hydrates. A minor part of the As retained in the tailings was assumed to be As (III)-species. Weathering cell tests (WCT) involving 32 weekly cycles of wetting and air exposure were conducted to assess the effect of weathering on the stability of As in the tailings. As-bearing Fe-hydrates remained intact during the early stages of the WCT; the low release of As during this period was probably due to the dissolution of solubleAs(III)-phases. During the later stages of the WCT, the release of As, Fe and S increased due to pyrrhotite oxidation and the destabilization of As-bearing Fe-hydrates. The majority of the originally present As was still associated with the tailings by the end of the test, but additional pyrrhotite oxidation with the pH falling to >3 could further destabilize these As-bearing Fe-hydrates. In the second part of the study,cyanided tailings were converted into a monolith by using a method called cemented paste backfill (CPB). Two mixtures of CPB were tested; CE with 1 wt. % of cement and CE-FA consisting 2 weight (wt.) % of cement together with 1 wt. % of biofuel fly ash. The stability of As in CPB-masses andun-amended tailings were evaluated using tank leaching tests (TLT) and WCT: s. TheTLT results showed that the CPB mixtures were not suitable for use inunderground backfilling because the As content of the CPB leachates increasedcontinuously over the course of the tests. The proportion of binders inCPB-materials is usually 3-7% because such loadings are required to create amonolithic mass that physically and chemically stabilizes arsenic species intailings. The addition of small quantities of binders in CE and CE-FA maytherefore have been insufficient to ensure that the monoliths were highly saturated, which is required to prevent the transport of oxygen and water through the CPB material. In the WCT, crushed CPB materials were used and the addition of binders caused only a minor increase in the leaching of As relative to that seen with unmodified tailings. The addition of binders has re-located a minor proportion of As in As-bearing Fe-hydrates into less acid-tolerant species. During the later stages of the WCTs, the CPB mixtures were treated with acid in order to consume the buffering minerals and simulate the formation of acid mine drainage (AMD). When acid was added to crushed CPB-materials, As-release increased due to the dissolution of Fe-hydrates. The addition of binders into tailings could pose more resistance to sulphide oxidation, which in turn means that the stability of As-bearing Fe-hydrates could be prolonged on long term. Results from the WCT suggested that the addition of low proportions of binders could have a positive effect on As-leaching in a long term perspective. A relatively new method called “Surfacepaste disposal” (SPD), where mixtures of low proportions of binders and tailings is placed as a cover on the un-amended tailings has shown promising results in terms of decreasing As-leaching and the generation of AMD. Future research will, therefore, focus on the stability of As in SPD-applications.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2014. p. 55
Series
Licentiate thesis / Luleå University of Technology, ISSN 1402-1757
National Category
Geochemistry
Research subject
Applied Geology
Identifiers
urn:nbn:se:ltu:diva-17804 (URN)54cded1a-eaee-4736-a3cb-b42413e37694 (Local ID)978-91-7583-071-1 (ISBN)978-91-7583-072-8 (ISBN)54cded1a-eaee-4736-a3cb-b42413e37694 (Archive number)54cded1a-eaee-4736-a3cb-b42413e37694 (OAI)
Note
Godkänd; 2014; 20141015 (rogham); Nedanstående person kommer att hålla licentiatseminarium för avläggande av teknologie licentiatexamen. Namn: Roger Hamberg Ämne: Tillämpad geologi/Applied Geology Uppsats: Characterization and Solidification of Arsenic-rich Cyanided Tailings Examinator: Biträdande professor Lena Alakangas, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Diskutant: Fil. lic / Enhetschef Bergteknik Lena Sultan, Ramboll Sverige AB Tid: Torsdag den 4 december 2014 kl 13.00 Plats: E246, Luleå tekniska universitetAvailable from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-05-04Bibliographically approved
Alakangas, L. & Hamberg, R. (2014). Project: ERA-MIN project "Tools for sustainable gold mining in EU". Paper presented at .
Open this publication in new window or tab >>Project: ERA-MIN project "Tools for sustainable gold mining in EU"
2014 (English)Other (Other (popular science, discussion, etc.))
Abstract [en]

This research identifies and evaluates environmental impacts and economical challenges of gold mining in Finland, Sweden, Portugal, Romania, Poland and Ireland. The focus of this project is in gold exploration, mineral processing, water treatment, waste management, environmental monitoring, risk assessment and socio-economic impacts of gold mining. Finasieras av Vinnova

National Category
Geochemistry
Research subject
Applied Geology
Identifiers
urn:nbn:se:ltu:diva-36298 (URN)e7e8788e-fe58-4329-adee-d8759126a2d4 (Local ID)e7e8788e-fe58-4329-adee-d8759126a2d4 (Archive number)e7e8788e-fe58-4329-adee-d8759126a2d4 (OAI)
Note

Status: Ongoing; Period: 01/01/2014 → 31/12/2017

Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2019-11-22Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-5010-4815

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