A Single Step Acid Assisted Microwave Digestion Method for the Complete Dissolution of Bauxite and Quantitation of its Composition (Al₂O₃, Fe₂O₃, SiO₂, TiO₂, Cr₂O₃, MgO, MnO and V₂O₅) by ICP‐AES

Abstract

The method was validated with respect to ruggedness, linearity, trueness, precision, limit of detection (LOD), limit of quantification (LOQ), working range and measurement uncertainties by analysing a bauxite reference material (Alcan BXT-12) and four certified reference materials (IPT-131, BXBA-4, NIST SRM 600, NIST SRM 697). The expanded uncertainties obtained for Al 2 O 3 (40.0%), Fe 2 O 3 (17.0%), SiO 2 (20.3%), TiO 2 (1.31%), Cr 2 O 3 (0.024%), MgO (0.05), MnO (0.013), and V 2 O 5 (0.60%), were 0.80, 0.40, 0.50, 0.033, 0.0008, 0.002, 0.0007 and 0.002 respectively, which are fit for the intended use to characterise bauxite. The developed method was also evaluated through participation in an interlaboratory comparison exercise organised by the Jawaharlal Nehru Aluminium Research Development and Design Centre (JNARDDC), Nagpur, India, using bauxite sample (BXT-JNA), with satisfactory z-scores achieved.

Production of Bauxite Certified Reference Material (BARC‐B1201) for Nine Property Values (Al2O3, Fe2O3, SiO2, TiO2, V2O5,MnO, Cr2O3, MgO and LOI) Traceable to SI Units

“…Candidate bauxite RMs were digested using the method described in our previous paper (Prasad et al . 2023). In brief, ~ 0.2 g of bauxite sample (W S ) was placed in a microwave vessel (PTFE) followed by sequential addition of 1 ml of HF, 4 ml H 3 PO 4 and 4 ml H 2 SO 4 to the vessels; the microwave vessels were sealed and placed in the microwave digestion system (Programme: power 800 W; ramp 15 min; hold time 45 min).…”

“…The minimum representative mass of sample was determined from the relative standard deviation of ten replicates of 200 mg from the processed bulk material using the validated SSBD ICP‐AES method (Prasad et al . 2023). The homogeneity of all property values in the processed bulk material (i.e., after grinding, sieving and mechanical homogenisation) was assessed using samples taken from ten different locations from the bulk material.…”

Analysis of PbBi eutectic after matrix separation by acid induced dispersive liquid–liquid microextraction followed by HR-CS-ETAAS determination

“…Recently, Dash et al reported complete dissolution of geological samples using the mixed acids in which a variety of elements were stabilised in solution for their determination by ICP-AES. 31 Procedural blanks were also prepared similarly without a sample.…”