Webinar: Resource Assessment and Profitability of Heavy Mineral Deposits

Welcome & What This Session Covers

Welcome! In this session we focus on the resource assessment and profitability of heavy mineral sand deposits. You’ll learn how to define geological domains, distinguish total heavy minerals (THM) from valuable heavy minerals (VHM), optimize cut-off grades with stripping ratio and recovery, select interpolation methods, and validate economic viability. Follow K-MINE on LinkedIn to keep up with webinars, case studies, and product updates.

About K-MINE

Founded in 1994 in Ukraine, K-MINE has grown across Europe, the United States, and Canada. Our team blends software engineers, geologists, and mining engineers, including Qualified Persons able to prepare technical reports to NI 43-101, JORC, and SEC S-K 1300 standards. We support exploration through production for open-pit and underground operations, with optional Dispatch/IoT integration for real-time monitoring.

Why Heavy Mineral Sands Matter

Titanium and zirconium supply chains rely heavily on deposits containing ilmenite, rutile, leucoxene, and zircon. While placer and palaeoplacer systems remain the most worked and profitable in the near term, magmatic and other deposit styles contribute significant global TiO₂ units. Understanding deposit type and mineral assemblage is essential to realistic project economics.

From Sediments to Ore: Deposit Architecture

Coastal processes—waves, longshore currents, tides, and wind—concentrate dense minerals into laminated or lens-shaped bodies that can reach several metres to tens of metres thick. Post-depositional processes (erosion of older shorelines, reworking into aeolian dunes, redox fronts, river input, compaction, acid sulfate soil development) strongly influence grade distribution and mining selectivity.

Geological Domaining That Reflects Metallurgy

Define domains by sedimentary facies, mineral associations, grain size, and secondary alteration (e.g., weathering, clay layers, sulfides). Build closed wireframes and/or surfaces, and code them to the block model. Ensure mineralogical sampling is representative so materials from different domains aren’t blended into a single composite that masks variability.

Sampling, Compositing & Laboratory Methods

Routine samples are often screened for heavy mineral concentrate (HMC) yield via heavy liquid separation; only intervals above threshold progress to detailed mineral assemblage work. Composite formation typically involves drying, quartering, heavy liquid separation, and preparation of HMC for analysis. Assemblage can be determined by automated mineralogy (e.g., QEMSCAN/MLA) and/or staged magnetic/electrostatic separations with XRF.
Quality assurance is critical: submit standards, blanks, and duplicates at appropriate frequencies and monitor performance during the program—not only at data preparation.

Units That Drive Tonnes & Grade

Where legacy reporting uses kg/m³, bulk density of sands becomes pivotal for converting grades and calculating tonnage. Minimum ore thicknesses of ~2 m are common; very high grades may justify thinner intercepts, subject to geotechnical and mining constraints.

Cut-Off Grade, Stripping Ratio & Break-Even Logic

Economic cut-offs should consider mining cost, processing cost, recoveries, and product pricing—plus overburden. A practical way to express this for ilmenite in kg/m³ is:
Break-even Ilmenite = A + B × K
where A is the zero-overburden break-even grade, B is the incremental kg/m³ per unit stripping ratio, and K is the overburden:ore thickness or volume ratio. Example: 42 + 2.6 × K (kg/m³). Validate these inputs with current costs, recoveries, and price decks.

THM vs VHM—Measuring What Pays

THM (e.g., ≥1% as a screening threshold in many operations) is a useful first filter, but value is driven by VHM (ilmenite, rutile, leucoxene, zircon, etc.). Areas with modest THM can be highly valuable if zircon or rutile proportions are elevated. Use assemblage data and recoveries to convert THM to payable VHM and set domain-specific cut-offs.

Converting to a Single Value Metric (Ilmenite-Equivalent)

To compare blocks consistently, convert each payable mineral to an Ilmenite-Equivalent (Ilm-Eq) or $/t index by multiplying mineral content by its recovery and a price ratio relative to ilmenite. Summing across minerals yields a standardized value field for optimization and cut-off selection—especially helpful where assemblage varies across the deposit.

Depth, Overburden & Economic Filters

Account for mining depth and overburden using coefficients that penalize intervals/blocks with high K ratios. This highlights zones where value per tonne of sand outweighs overburden removal costs and segregates marginal/sub-economic material that may upgrade with technology or price cycles. This aligns with “reasonable prospects for eventual economic extraction” in JORC and other codes.

Interpolation & Classification

Common interpolation methods include inverse distance weighting (IDW), nearest neighbour (NN), and ordinary kriging (OK). Use only samples from the correct geological domain. Typical drill grids might range from ~60×60 m or 50×20 m (often sufficient for Measured) to 120×120 m or 250×50 m (Indicative of Indicated), and ≥400×50 m for Inferred, subject to variography and anisotropy.
For OK, the kriging slope of regression is a useful guide: >0.85 supports Measured (with other criteria met), 0.70–0.85 supports Indicated, and <0.70 is Inferred.

Reporting Conventions

Follow reporting codes when rounding: tonnages to two significant figures; percentages for THM/VHM typically to two or three significant figures as appropriate; mineral associations and oversize/clay to whole numbers. Ensure transparency on domaining, compositing, top-cuts (if any), and QA/QC performance.

Beyond TiO₂: Co-Products & By-Products

In addition to ilmenite, rutile/leucoxene, and zircon, mineral sands may yield kyanite, sillimanite, and staurolite concentrates. By-product opportunities include Ta₂O₅, Nb, V, Sc, Hf, and REEs from monazite/xenotime; emerging studies also examine Ga and Ge in certain settings. Co-product credits can materially improve project economics.

Market Drivers & Outlook

TiO₂ pigments underpin demand in paints, paper, and plastics; titanium metal serves aerospace, defense, and medical applications; zircon supports ceramics and refractories. Energy transition, urbanization, and advanced manufacturing continue to drive demand for mineral sands products, guiding exploration and capital allocation.

How K-MINE Helps

K-MINE unifies geology, domaining, resource estimation, mine design, and scheduling in one desktop platform, with optional Dispatch/IoT for real-time KPIs. Our consulting team—led by Qualified Persons—prepares NI 43-101/JORC/S-K 1300–compliant studies, from exploration targeting to feasibility. We’ve supported leading titanium producers across Eastern Europe on zircon, rutile, ilmenite, kyanite, sillimanite, and related by-products.