IMA–CNMNC approved mineral symbols

Warr, Laurence N.

doi:10.1180/mgm.2021.43

Cited by 583 publications

(222 citation statements)

References 3 publications

Supporting

Mentioning

209

Contrasting

Unclassified

Order By: Relevance

“…Hem, hematite; Cal, calcite; Sme, smectite; Qz, quartz; Gp, gypsum; Py, pyrite; Sd, siderite; Crs, cristobalite; Kln, kaolinite; Ann, annite; Or, orthoclase; Sa, sanidine; Ab, albite; Ant, anatase; Rt, rutile. IMA-CNMNC-approved mineral symbols are used[30]; 0.1, 1, 4 and 7 indicate distance in cm from the heating tube.…”

mentioning

confidence: 99%

Thermally Induced Bentonite Alterations in the SKB ABM5 Hot Bentonite Experiment

et al. 2021

Self Cite

View full text Add to dashboard Cite

Pilot sites are currently used to test the performance of bentonite barriers for sealing high-level radioactive waste repositories, but the degree of mineral stability under enhanced thermal conditions remains a topic of debate. This study focuses on the SKB ABM5 experiment, which ran for 5 years (2012 to 2017) and locally reached a maximum temperature of 250 °C. Five bentonites were investigated using XRD with Rietveld refinement, SEM-EDX and by measuring pH, CEC and EC. Samples extracted from bentonite blocks at 0.1, 1, 4 and 7 cm away from the heating pipe showed various stages of alteration related to the horizontal thermal gradient. Bentonites close to the contact with lower CEC values showed smectite alterations in the form of tetrahedral substitution of Si4+ by Al3+ and some octahedral metal substitutions, probably related to ferric/ferrous iron derived from corrosion of the heater during oxidative boiling, with pyrite dissolution and acidity occurring in some bentonite layers. This alteration was furthermore associated with higher amounts of hematite and minor calcite dissolution. However, as none of the bentonites showed any smectite loss and only displayed stronger alterations at the heater–bentonite contact, the sealants are considered to have remained largely intact.

show abstract

mentioning

confidence: 99%

Thermally Induced Bentonite Alterations in the SKB ABM5 Hot Bentonite Experiment

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…In comparison to SD80, B36 showed higher concentrations of SiO 2 and K 2 O, which are associated with larger amounts of accessory minerals (~35 wt.%), i.e., feldspar, quartz and cristobalite. The 060-reflection of the randomly oriented powders were between 0.149 and 0.152 nm (Table 3) and correspond to dioctahedral smectite [38]. The 001reflection of the oriented slides in air-dried condition (~60% RH) was located around 1.5 nm, which is characteristic of smectite with bivalent interlayer cations (Ca 2+ and/or Mg 2+ ) hydrated by two water layers [39].…”

Section: Characterization Of Starting Materialsmentioning

confidence: 99%

Bentonite Alteration in Batch Reactor Experiments with and without Organic Supplements: Implications for the Disposal of Radioactive Waste

et al. 2021

Self Cite

View full text Add to dashboard Cite

Bentonite is currently proposed as a potential backfill material for sealing high-level radioactive waste in underground repositories due to its low hydraulic conductivity, self-sealing ability and high adsorption capability. However, saline pore waters, high temperatures and the influence of microbes may cause mineralogical changes and affect the long-term performance of the bentonite barrier system. In this study, long-term static batch experiments were carried out at 25 °C and 90 °C for one and two years using two different industrial bentonites (SD80 from Greece, B36 from Slovakia) and two types of aqueous solutions, which simulated (a) Opalinus clay pore water with a salinity of 19 g·L−1, and (b) diluted cap rock solution with a salinity of 155 g·L−1. The bentonites were prepared with and without organic substrates to study the microbial community and their potential influence on bentonite mineralogy. Smectite alteration was dominated by metal ion substitutions, changes in layer charge and delamination during water–clay interaction. The degree of smectite alteration and changes in the microbial diversity depended largely on the respective bentonite and the experimental conditions. Thus, the low charged SD80 with 17% tetrahedral charge showed nearly no structural change in either of the aqueous solutions, whereas B36 as a medium charged smectite with 56% tetrahedral charge became more beidellitic with increasing temperature when reacted in the diluted cap rock solution. Based on these experiments, the alteration of the smectite is mainly attributed to the nature of the bentonite, pore water chemistry and temperature. A significant microbial influence on the here analyzed parameters was not observed within the two years of experimentation. However, as the detected genera are known to potentially influence geochemical processes, microbial-driven alteration occurring over longer time periods cannot be ruled out if organic nutrients are available at appropriate concentrations.

show abstract

“…All three new minerals and their names have been approved by the International Mineralogical Association (IMA) Commission on New Minerals, Nomenclature and Classification (CNMNC): IMA2019-081 [alexkuznetsovite-(La), Kasatkin et al, 2019c], IMA2019-118 [alexkuznetsovite-(Ce), Kasatkin et al, 2020d] and IMA2020-020 [biraite-(La), Kasatkin et al, 2020e]. The mineral symbol (Warr, 2021) for alexkuznetsovite-(La) and alexkuznetsovite-(Ce) is Alx-La and Alx-Ce, respectively, and biraite-(La) is Bir-La. The type specimens are deposited in the systematic collection of the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow with the catalogue numbers: alexkuznetsovite-(La) -97005 (holotype), 97024 and 97025 (parts of holotype); alexkuznetsovite-(Ce) -97008 (holotype) and 97026 (cotype); biraite-(La) -97023 (holotype).…”

Section: Introductionmentioning

confidence: 99%

The mineralogy of the historical Mochalin Log REE deposit, South Urals, Russia. Part IV. Alexkuznetsovite-(La), La₂Mn(CO₃)(Si₂O₇), alexkuznetsovite-(Ce), Ce₂Mn(CO₃)(Si₂O₇) and biraite-(La), La₂Fe²⁺(CO₃)(Si₂O₇), three new isostructural minerals and a definition of the biraite group

Kasatkin

Zubkova

Pekov

et al. 2021

MinMag

View full text Add to dashboard Cite

show abstract

IMA–CNMNC approved mineral symbols

Abstract: This is a 'preproof' accepted article for Mineralogical Magazine. This version may be subject to change during the production process.

Cited by 583 publications

References 3 publications

Thermally Induced Bentonite Alterations in the SKB ABM5 Hot Bentonite Experiment

Thermally Induced Bentonite Alterations in the SKB ABM5 Hot Bentonite Experiment

Bentonite Alteration in Batch Reactor Experiments with and without Organic Supplements: Implications for the Disposal of Radioactive Waste

Contact Info

Product

Resources

About

IMA–CNMNC approved mineral symbols

Abstract: This is a 'preproof' accepted article for Mineralogical Magazine. This version may be subject to change during the production process.

Cited by 583 publications

References 3 publications

Thermally Induced Bentonite Alterations in the SKB ABM5 Hot Bentonite Experiment

Thermally Induced Bentonite Alterations in the SKB ABM5 Hot Bentonite Experiment

Bentonite Alteration in Batch Reactor Experiments with and without Organic Supplements: Implications for the Disposal of Radioactive Waste

The mineralogy of the historical Mochalin Log REE deposit, South Urals, Russia. Part IV. Alexkuznetsovite-(La), La2Mn(CO3)(Si2O7), alexkuznetsovite-(Ce), Ce2Mn(CO3)(Si2O7) and biraite-(La), La2Fe2+(CO3)(Si2O7), three new isostructural minerals and a definition of the biraite group

Contact Info

Product

Resources

About