Heavy mineral resource potential of Tista river sands, Northern Bangladesh

Abstract

Surface and borehole sampling along a ∼80 km section of the lower Tista river, northwestern Bangladesh, indicated that the river sands offer significant potential as a heavy mineral (HM) resource. Characterisation of sediments from the surface to 15 m depth showed that the sand-sized component was dominated by quartz, feldspar, mica, lithic fragments, amphibole and pyroxene group minerals. The most common particle size was between +125–500 μm with 84 wt-% of all material reporting to this size range. Laterally spaced sampling indicated slight grain size coarsening upstream. Heavy liquid separation studies revealed that HMs such as amphiboles, micas, garnets, aluminosilicate (Al2SiO5) phases, ilmenite and zircon made up ∼10.99% (on average). The percentage of valuable HMs (ilmenite, rutile, zircon, monazite, garnet) was 2.47% (average). Detailed borehole sampling and resource mapping of a large, mid-channel sand bar showed that placer-style HM accumulations occur upstream and along the margins of the bar.

Deciphering the Complex Mineralogy of River Sand Deposits through Clustering and Quantification of Hyperspectral X-Ray Maps

“…This work continues an earlier study by Biswas et al (2018) which investigated the economic potential for heavy mineral extraction from the sand bar deposits of the Tista River in northern Bangladesh. In that study, specimens of sand were sampled from along the river banks at Rajpur some 45 km from the confluence with the Brahmaputra River, as well as at 45 points on the network of mid-channel sand bars using a grid 4.5 km long and 2.5 km wide.…”

“…The feedstock materials studied in this investigation were the D4 shaker and bulk 1 shaker specimens described in Biswas et al (2018). The heavy minerals (i.e., specific gravity >2.6 g/cm 3 ) in these samples were concentrated using a shaking table to remove unwanted light minerals, followed by a wash in 1 M HCl and distilled water to remove carbonate minerals (e.g., calcite, dolomite).…”

“…The final phase maps of all four specimens are given in Figure 15, along with the modal analyses of phase abundances in Table 3. The XRD quantitative phase analysis of the same D4 shaker and Bulk 1 shaker heavy concentrate specimens reported by Biswas et al (2018) are reproduced in Table 3 for comparison.…”

“…The authors also acknowledge the Project Director, Mineral Processing Center at IMMM of BCSIR for supporting the assignment of Pradip Biswas as a Visiting Scientist at CSIRO. Furthermore, the authors wish to acknowledge the contribution of Cameron Davidson of the CSIRO for preparing samples for EPMA analysis, Stephen Peacock for performing the bulk XRF analyses, and Dr. Anita D'Angelo for performing the quantitative XRD analysis from the Biswas et al (2018) study, a portion of which was reproduced herein. The authors would lastly like to thank Dr. Nathan Webster of the CSIRO for his careful review of the manuscript and also the journal referee whose insightful comments resulted in a more thorough treatment of trace element detection.…”

Geochemical signatures of recent bar deposits in the Tista river, Bangladesh: Implications to provenance, paleoweathering and tectonics

“…Thereafter, Hossain et al (2013) focused on glass sand potentiality, and Rahman et al (2017) introduced techno-economic viability of the river deposits. Biswas et al (2018) sediments for provenance, tectonics and weathering implications.…”