Soil salinization during the development of primary diamond deposits in the cryolithozone (Western Yakutia (Russia))
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-09-26 |
| Journal | Bulletin of the Tomsk Polytechnic University Geo Assets Engineering |
| Authors | Olesya Shadrinova, Yana Legostaeva |
| Analysis | Full AI Review Included |
Technical Documentation and Analysis: Soil Salinization in Cryolithozone Diamond Mining
Section titled âTechnical Documentation and Analysis: Soil Salinization in Cryolithozone Diamond MiningâExecutive Summary
Section titled âExecutive SummaryâThis research highlights critical environmental degradation challengesâtechnogenic soil salinizationâresulting from primary diamond mining operations in the Western Yakutia cryolithozone. The extreme conditions (permafrost acting as a geochemical barrier, high concentrations of corrosive salts, and alkaline pH) necessitate ultra-robust monitoring and remediation technologies.
- Core Challenge: Mining waste (dumps and tailings) introduce highly toxic, soluble salts ($Na_{2}SO_{4}$, $MgSO_{4}$, $MgCl_{2}$, NaCl) into the soil profile, leading to widespread salinization (up to 0.18 cmol(eq)/kg $S_{tox}$).
- Environmental Barrier: The continuous permafrost (Multi-Year Permafrost, MMP) acts as a hydrological barrier, preventing the downward leaching of salts and forcing accumulation in the shallow seasonal thaw layer (STS).
- Material Requirement: Monitoring and remediation efforts require materials that are chemically inert, resistant to high concentrations of chlorides and sulfates, and stable across extreme temperature cycles (cryolithozone conditions).
- 6CCVD Value Proposition: Boron-Doped Diamond (BDD) electrodes and sensors are the ideal solution for real-time, in-situ electrochemical monitoring of toxic ions ($Cl^{-}$, $SO_{4}^{2-}$, $Na^{+}$, $Mg^{2+}$) in these highly corrosive, alkaline (pH up to 8.4) environments.
- Customization for Deployment: 6CCVD offers custom BDD film deposition, specialized metalization (e.g., Ti/Pt/Au contacts), and robust SCD/PCD substrates for integrating high-performance electronics into remote, harsh-environment monitoring systems.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the analysis of soil water-soluble complexes in the industrial zone (Aykhal Mining and Processing Plant, AMPP):
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Maximum Toxic Salt Total ($S_{tox}$) | 0.18 $\pm$ 0.12 | cmol(eq)/kg | Soils affected by tailing dumps |
| Average Toxic Salt Total ($S_{tox}$) | 0.14 $\pm$ 0.03 | cmol(eq)/kg | Soils affected by waste rock dumps |
| Natural Soil pH ($pH_{H2O}$) | 6.7 $\pm$ 0.4 | N/A | Background natural landscapes |
| Tailing Dump Soil pH ($pH_{H2O}$) | 7.7 $\pm$ 0.4 | N/A | Slightly alkaline |
| Toxilitostrats Soil pH ($pH_{H2O}$) | 8.4 $\pm$ 0.6 | N/A | Highly alkaline |
| Dominant Anion (Waste Dumps) | 1.96 $\pm$ 0.58 | cmol(eq)/kg | Sulfate ($SO_{4}^{2-}$) concentration |
| Dominant Cation (Waste Dumps) | 1.60 $\pm$ 0.46 | cmol(eq)/kg | Sodium + Potassium ($Na^{+}$+$K^{+}$) concentration |
| Dominant Anion (Tailing Dumps) | 2.31 $\pm$ 1.04 | cmol(eq)/kg | Sulfate ($SO_{4}^{2-}$) concentration |
| Maximum Chloride Concentration | 1.11 $\pm$ 2.45 | cmol(eq)/kg | Tailing dumps (marker for brine impact) |
| Salinization Type (Waste Dumps) | Sulfate, Chloride-Sulfate | N/A | Medium degree of salinity |
| Salinization Type (Tailing Dumps) | Chloride, Sulfate-Chloride | N/A | Strong to very strong degree of salinity |
Key Methodologies
Section titled âKey MethodologiesâThe study focused on analyzing the geochemical transformation of soils and technogenic surface formations (Technosols) resulting from diamond mining activities in the cryolithozone.
- Sampling: Field sampling was conducted in August 2019 and 2023, during maximum soil thaw, covering natural landscapes, waste dumps (Litostrats), and tailing dumps (Toxilitostrats).
- Sample Preparation: Samples were dried and sieved through a 1 mm mesh.
- Chemical Analysis (Water Extract 1:5): Major cations ($Ca^{2+}$, $Mg^{2+}$, $Na^{+}$+$K^{+}$) and anions ($CO_{3}^{2-}$, $HCO_{3}^{-}$, $Cl^{-}$, $SO_{4}^{2-}$) were determined.
- pH Measurement: Measured in a soil:water suspension (1:5) at room temperature using a Mettler Toledo Seven Compact Advanced pH meter.
- Organic Matter: Determined using the photoelectric colorimetric method.
- Toxic Salt Calculation: The total of toxic salts ($S_{tox}$) was calculated based on the content of $Na_{2}CO_{3}$, $MgCO_{3}$, $NaHCO_{3}$, $Mg(HCO_{3}){2}$, $Na{2}SO_{4}$, $MgSO_{4}$, $NaCl$, $MgCl_{2}$, and $CaCl_{2}$.
- Geochemical Barrier Identification: The soil profiles were analyzed to identify evaporative, biogenic, and permafrost geochemical barriers responsible for salt accumulation.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe extreme geochemical conditions identified in the Alakit-Markha kimberlite fieldâspecifically high salinity, high alkalinity, and the presence of highly corrosive chloride and sulfate ionsâpresent a perfect use case for diamond-based electrochemical and structural materials.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate or extend this research into real-time monitoring, environmental remediation, or robust electronics deployment, 6CCVD recommends the following materials:
-
Boron-Doped Diamond (BDD) Electrodes:
- Application: Essential for robust, long-term, in-situ electrochemical sensing of toxic ions ($Cl^{-}$, $SO_{4}^{2-}$, $Na^{+}$, $Mg^{2+}$) and pH monitoring.
- Advantage: BDD exhibits unparalleled chemical inertness and a wide potential window, making it resistant to fouling and corrosion by the high concentrations of sulfates and chlorides (up to 2.45 cmol(eq)/kg $Cl^{-}$) and the alkaline environment (pH up to 8.4) found in the Toxilitostrats.
- Format: Custom BDD films (0.1”m - 500”m thickness) deposited on silicon or refractory metal substrates, tailored for sensor arrays.
-
High Thermal Conductivity SCD/PCD Substrates:
- Application: Substrates for high-power electronics, communication modules, and sensor control units operating in the cryolithozone, where extreme temperature cycling (from -48.9 °C in January to 18.3 °C in July) demands superior thermal management.
- Advantage: SCD and PCD offer the highest known thermal conductivity, ensuring reliability and longevity of deployed electronics in remote, harsh environments.
- Format: Inch-size PCD wafers (up to 125mm) or high-purity SCD plates for critical components.
Customization Potential
Section titled âCustomization PotentialâThe deployment of environmental monitoring systems in remote mining infrastructure requires highly specific, durable components. 6CCVD provides comprehensive customization services:
| Custom Requirement | 6CCVD Capability | Relevance to Research |
|---|---|---|
| Custom Dimensions | Plates/wafers up to 125mm (PCD). Substrates up to 10mm thickness. | Manufacturing large-area sensor arrays for spatial mapping of salinization (as shown in Fig. 8). |
| BDD Film Thickness | SCD and PCD films available from 0.1”m to 500”m. | Optimizing BDD electrode performance (conductivity vs. cost) for specific electrochemical applications (e.g., anodic oxidation for remediation). |
| Metalization | Internal capability for Au, Pt, Pd, Ti, W, Cu deposition. | Creating robust, corrosion-resistant electrical contacts (e.g., Ti/Pt/Au stack) on BDD sensors for long-term field deployment in saline/alkaline soils. |
| Polishing | Ultra-smooth surfaces: Ra < 1nm (SCD), Ra < 5nm (Inch-size PCD). | Ensuring optimal surface quality for sensor interfaces and high-reliability electronic packaging. |
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house team of PhD material scientists specializes in optimizing diamond properties for extreme applications. We recognize that the unique combination of permafrost, high alkalinity, and corrosive salts in this Cryolithozone Environmental Monitoring project demands specialized material selection. Our experts can assist researchers and engineers in:
- Selecting the optimal BDD doping level and film thickness for maximum sensitivity and stability in high-chloride/sulfate brines.
- Designing custom metalization schemes that withstand the corrosive geochemical barriers identified in the soil profiles.
- Providing thermally robust SCD/PCD substrates for reliable sensor electronics operating under extreme temperature fluctuations.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Relevance. Soil salinization is one of the major contributors to land degradation, which leads to changes in microbial and biochemical properties of soil, loss of biological diversity, desertification and disruption of ecosystem functioning in general. This article presents the results of studying the processes of technogenic salinization of soil cover in the north taiga landscape province within the continuous permafrost zone based on the example of mining area of the primary diamond deposits in Western Yakutia in the Yakutsk diamondiferous province (Alakit-Markha kimberlite field). Aim. Study of soil salinization processes in diamond mining within the continuous permafrost zone and identification of the causes for technogenic pedohalogenesis development. Methods. Major cations and anions, pH were determined in water extract (1:5), soil organic matter was determined using photoelectric colorimetric method. The total of toxic salts was calculated. Statistical analysis was conducted in Statistica10 program. Map-schemes of area distribution of soil salinization and totals of toxic salts were plotted using Surfer-13 program by kriging interpolation method. Result and conclusions. It was established that the processes of technogenic soil salinization due to diamond mining have acquired an areal character, being confined to the mining and processing facilities of the processing plant. In the impact area of waste dumps, predominantly sulfate type of salinization is observed, with the prevalence of toxic salts such as Na2SO4, MgSO4 and MgCl2. A marker of tailing dumps impact includes occurrence of chloride type of salinization and toxic salts, such as Na2SO4, MgSO4 and MgCl2, NaCl. Soil profile of technogenically salinized soils is distinguished by the presence of evaporative, biogenic or permafrost geochemical barriers, which displays the specific nature of salinization processes.