Digestion method and detection method for iron ore

Abstract

The invention provides a digestion method and a detection method for iron ore. The digestion method comprises the following steps: adding an iron ore sample in which hydrofluoric acid and nitric acid (or sulfuric acid) are mixed, then carrying out high-pressure closed microwave digestion to obtain a suspension; and heating the suspension in an unclosed system to secure the second digestion with residual nitric acid (or residual sulfuric acid) and added perchloric acid and hydrogen peroxide, thereby obtaining a solution which is digested fully. The detection method comprises the following steps: preparing a solution with the digested solution, and detecting the prepared solution by inductive coupling plasma atomic emission spectrometry, thereby obtaining content of each element of the iron ore sample. The invention has the advantages of high efficiency, high accuracy, and simple and fast process. Especially, the invention realizes accurate detection of key element content in iron ore, such as As, Pb, Zn, W, Sn, Ca, Mg, Cu, Co, Ni, Cr and Mo which affect product quality of iron and steel smelting and vanadium / titanium extraction.

Description

technical field [0001] The invention relates to the technical field of analysis and detection of compounds, more specifically, to iron ore categories, especially to digestion methods and detection methods of various types of vanadium-ilmenite. Background technique [0002] Vanadium ilmenite (including raw ore, concentrate, tailings, sinter, pellet ore and oxidized ilmenite, etc. containing vanadium, titanium, and iron, hereinafter also referred to as vanadium ilmenite samples) is different from ordinary Iron ore, its composition and phase structure are very complex, and usually contains about 10% TiO 2 and a few percent of V 2 o 5 . For example, there are very rich vanadium-titanium magnetites in the Panxi region of my country. These vanadium-titanium magnetites are multi-element paragenetic ores with complex compositions and phase structures, and the composition of different ore sites is also quite different. In addition to containing major elements such as Fe, V, Ti, Si...

AI Technical Summary

Problems solved by technology

[0009] ① After microwave digestion, a suspension will be formed, and there are many residues in the suspension, which makes the digestion not thorough enough

Mainly reflected in two points: First, microwave digestion usually requires the use of hydrofluoric acid, however, the hydrofluoric acid remaining in the digestion solution will seriously corrode the detection instruments used in subsequent detection steps

If the detection instrument is replaced with special parts with anti-corrosion ability, it will usually reduce the important technical performance such as transmission atomization efficiency, and the method of reducing the corrosion of hydrofluoric acid by boric acid complexation will increase the types of salt in the solution to be tested , which makes the matrix of the solution to be tested more complex, which leads to more factors that interfere with the detection and affects the accuracy of the detection results; the second is that after microwave digestion, the high content of silicon in the vanadium ilmenite is not removed and remains in the solution , leading to an increase in the complexity of the matrix and the concentration of salts, thereby interfering with the accuracy of the detection of elements in vanadium-titanium-magnetite samples

[0011] ③In order to ensure safety, it is generally necessary to avoid the use of strong oxidizing perchloric acid, hydrogen peroxide and sulfuric acid reagents when digesting vanadium-titanite samples in a microwave sealed environment, which will lead to carbon and nitrogen in titano-magnetite samples. Compounds cannot be effectively decomposed, affecting the accuracy of test results

Microwave digestion generally does not use perchloric acid because of its strong oxidizing properties, and there is a risk of explosion when it reacts with certain substances; hydrogen peroxide is not used mainly because it is easy to decompose to generate oxygen, resulting in too high pressure in the tank; sulfuric acid is not used because of its high density, High viscosity will have matrix effect on subsequent instrument determination

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