CN102323179A - Method for detecting sulfur dioxide in desulfurized gypsum - Google Patents

Abstract

The invention relates to a method for detecting sulfur dioxide in desulfurized gypsum, which belongs to the building material detection field, and is composed of a test reagent, a test apparatus, a sample preparation method, a test method and a calculating method. The invention is characterized in that the strong oxidation effect of the hydrogen peroxide under the acidic condition is used, and sulfur dioxide in desulfurized gypsum is directly oxidized into sulfur trioxide, so that the sulfur dioxide content and the gypsum purity in desulfurized gypsum can be obtained by using barium sulfate twice gravimetric method. The method of the invention is capable of providing a beneficial guidance to the operation of a desulphurization system as well as having the great effect to control the quality of gypsum products.

Description

The method of inspection of sulphuric dioxide in the desulfurated plaster

Technical field

The invention belongs to the building materials detection range, be specifically related to the method for inspection of sulphuric dioxide in the desulfurated plaster.

Background technology

" Chinese building material science and technology " 52 interim disclose " detection method of sulfuric anhydride and sulphuric dioxide in the gypsum " in 2010 in this piece article, have proposed that the detection employing iodimetric titration of sulphuric dioxide obtains in the gypsum.The shortcoming that iodimetric titration detects sulphuric dioxide is: the iodine amount that iodimetric titration needs accurate titration to consume, also can cause the consumption of iodine but in sample other are organic with dead matter, and operation easier is big, and test accuracy is relatively poor.

Summary of the invention

Carry out the detection of sulphuric dioxide in the gypsum for accurate, quick, cheapness, the present invention proposes the method for inspection of sulphuric dioxide in the desulfurated plaster.

The present invention utilizes oxydol that oxidizing sulfur dioxide in the gypsum is become sulfuric anhydride with reference to sulfuric anhydride weight detecting method in the desulfurated plaster, utilizes the barium sulphate gravimetric method to detect.Test findings with do not add the oxydol gypsum and compare, can draw content of sulfur dioxide in the gypsum.

The present invention is made up of test reagent, test apparatus, sample preparation methods, test method, computing method, it is characterized in that test reagent adopts 18% hydrochloric acid solution, 13% Ammonia, 1% liquor argenti nitratis ophthalmicus, 0.2% methyl red indicator solution, 10% barium chloride solution; Described 0.2% methyl red indicator solution is that 0.2 gram methyl red is dissolved in 100 milliliters of ethanol.Described 10% barium chloride solution is that 10 gram barium chlorides are dissolved in 100 ml waters.

Described test apparatus adopts one of high temperature furnace, conventional glass apparatus.

Said sample preparation methods is: accurately take by weighing desulfurated plaster sample 0.5 gram, place 250 ml beakers, be soaked in water 2 minutes, add 10% oxydol 5ml, cover the table ware and soaked 5 minutes; Slowly splash into 40 milliliter of 6% hydrochloric acid from rim of a cup, after question response stops, being settled to 75 milliliters behind water flushing surface plate and the wall of cup; Heated and boiled 3～4 minutes is used filter paper filtering at a slow speed, reacts (checking with liquor argenti nitratis ophthalmicus) with hot water wash to there being the chlorine root.Filtrating collects in 250 milliliters of volumetric flasks, puts coldly naturally, and water weighs and to release to 250 ml beaker graticules, shake up into sample solution subsequent use;

Said test method is to draw 50 milliliters of the above-mentioned sample solutions make; Put into 400 ml beakers; Add 180～200 ml waters and 1～2 0.2% methyl red indicator solution, drip 13% ammonium hydroxide to solution and be yellow, add 10 milliliter of 18% hydrochloric acid again; Solution is heated to boils, under agitation drip 15 milliliter of 10% barium chloride solution, continued heated and boiled 3～5 minutes, left standstill then 4 hours.Use filter paper filtering at a slow speed, and with till the hot wash more than 60 degrees centigrade to the chlorine root loss for reaction (checking with liquor argenti nitratis ophthalmicus).Sediment and filter paper are moved in the lump in the porcelain crucible of pre-burn calcination 30 minutes in 800 ℃ high temperature furnace after the ashing.Take out crucible, place exsiccator to naturally cool to room temperature, weighing.Calcination so repeatedly is until constant weight.

Described computing method are sulphuric dioxide percentage composition=0.275 * (G2-G1)/G * 100%;

In the above-mentioned formula: G-example weight;

Crucible weight before G1-calcination;

Crucible weight after G2-calcination;

0.275-barium sulphate is to the reduction coefficient of sulphuric dioxide.

The present invention utilizes the strong oxidation of oxydol under acid condition, and the sulphuric dioxide in the desulfurated plaster is direct oxidation into sulfuric anhydride, thereby utilizes twice gravimetric method of barium sulphate, can draw content of sulfur dioxide and gypsum purity in the desulfurated plaster.Operation can provide useful guide to desulphurization system in the present invention, for the quality of controlling gypsum product bigger effect is arranged.

Claims (1)

1. the method for inspection of sulphuric dioxide in the desulfurated plaster; Form by test reagent, test apparatus, sample preparation methods, test method, computing method, it is characterized in that test reagent adopts 18% hydrochloric acid solution, 13% Ammonia, 1% liquor argenti nitratis ophthalmicus, 0.2% methyl red indicator solution, 10% barium chloride solution;

Described 0.2% methyl red indicator solution is that 0.2 gram methyl red is dissolved in 100 milliliters of ethanol; Described 10% barium chloride solution is that 10 gram barium chlorides are dissolved in 100 ml waters;

Said sample preparation methods is: accurately take by weighing desulfurated plaster sample 0.5 gram, place 250 ml beakers, be soaked in water 2 minutes, add 10% oxydol 5ml, cover the table ware and soaked 5 minutes; Slowly splash into 40 milliliter of 6% hydrochloric acid from rim of a cup, after question response stops, being settled to 75 milliliters behind water flushing surface plate and the wall of cup; Heated and boiled 3～4 minutes is used filter paper filtering at a slow speed, reacts to there being the chlorine root with hot water wash; Filtrating collects in 250 milliliters of volumetric flasks, puts coldly naturally, and water weighs and to release to 250 ml beaker graticules, shake up into sample solution subsequent use;

Said test method is to draw 50 milliliters of the above-mentioned sample solutions make; Put into 400 ml beakers; Add 180～200 ml waters and 1～2 0.2% methyl red indicator solution, drip 13% ammonium hydroxide to solution and be yellow, add 10 milliliter of 18% hydrochloric acid again; Solution is heated to boils, under agitation drip 15 milliliter of 10% barium chloride solution, continued heated and boiled 3～5 minutes, left standstill then 4 hours; Use filter paper filtering at a slow speed, and with till the hot wash more than 60 degrees centigrade to the chlorine root loss for reaction; Sediment and filter paper are moved in the lump in the porcelain crucible of pre-burn calcination 30 minutes in 800 ℃ high temperature furnace after the ashing; Take out crucible, place exsiccator to naturally cool to room temperature, weighing; Calcination so repeatedly is until constant weight;

Described computing method are sulphuric dioxide percentage composition=0.275 * (G2-G1)/G * 100%;

In the above-mentioned formula: G-example weight;

Crucible weight before G1-calcination;

Crucible weight after G2-calcination;

0.275-barium sulphate is to the reduction coefficient of sulphuric dioxide.