CN102183518A - Method for quickly measuring sulfate radical content in magnesium method desulfurization process - Google Patents

Abstract

The invention discloses a method for quickly measuring sulfate radical content in a magnesium method desulfurization process. The method consists of the processes of filtration, constant volume determination, acidification, precipitation and back titration and comprises the following steps of: filtering a fetched sample by using filter paper; filling quantitative filtered clear solution with constant volume into a volumetric flask; filling proper constant volume clear solution in a beaker, and adding diluted hydrochloric acid of 1:1 concentration for acidifying; adding excessive barium chloride into the acidified clear solution to perform precipitation; filtering and fully washing the sediment, and titrating the total weight of barium, calcium and magnesium ions by using ethylene diamine tetraacetic acid (EDTA) coordination agent under the condition that chrome black T is used as an indicator; and meanwhile, calculating the content of the barium ions by measuring the total weight of the calcium and the magnesium so as to calculate the content of the sulfate radicals. The method has the advantages that: the control of solution concentration and measuring process conditions is accurate, the measurement of the content of the calcium and the magnesium is completed at the same time, and the preparation of barium and magnesium mixed solution is not needed; the accuracy of the sulfate radical detection is improved, and the detection time is shortened; and the method is suitable for quickly measuring the sulfate radical content in the debugging and operating process of a magnesium oxide method desulfurization system.

Description

The method of sulfate radical content in a kind of fast measuring magnesium method sweetening process

Technical field

The invention belongs to the assay method of sulfate radical content in the magnesium oxide method desulphurization system, particularly the method for quick of sulfate radical content in the slurries of magnesium method sweetening process absorption tower.

Background technology

The magnesium oxide method desulfurization is a sulfur method comparatively commonly used at present.In system's operation debug process, the content of sulfate radical directly influences magnesium sulfite in the slurries of absorption tower crystallization and slurries efflux control, in time measuring sulfate radical content becomes the important indicator of system's operation control, traditional detection method generally adopts gravimetric method, the method process is loaded down with trivial details, and detection time is longer, has increased testing staff's labour intensity on the one hand, the control data of system's operation can not in time be provided on the other hand, produce certain hysteresis quality.Hydro-extractor detection method in addition, it is bigger to be subjected to the influence of instrument condition control to measure the method error of sulfate radical, and because the Instrument measuring range is less, and very little error in reading will produce very big error, degree of accuracy is very poor in addition.Still do not have sulfate radical bioassay standard in the magnesium method desulphurization system slurries at present, the method is passed through the magnesium method desulfurizing item of a plurality of dissimilar sizes of reality, and accurate, the quick and adaptability of the method is determined in a large amount of experiments.

Summary of the invention

The objective of the invention is to design a kind of easy, quick, accurately measure the method for sulfate radical, be used in time providing magnesium method sweetening process system control data, save time, improve the accuracy of experimental data simultaneously, the method is measured sulfate radical in the absorption tower by adopting back titration method in the relatively accurate analytical chemistry, not only prevent the interference of other ions, and continued the experiment titration easy, accurately reach rapidity.

To the analysis of various materials in the magnesium oxide method desulfuration absorbing tower slurries, the main kation that comprises in magnesium method desulfurizer slurries has: Mg through for a long time ²⁺, Ca ²⁺Negative ion mainly contains: Cl ^-, SO ₄ ²⁺, SO ₃ ²⁺, the method is feasible through a large amount of experimental results show that.

For achieving the above object, technical scheme of the present invention is: the method for sulfate radical content in a kind of fast measuring magnesium method sweetening process, form by the technological process of filtration, constant volume, acidifying, precipitation, back titration.

Filter: with the absorption tower slurry samples filter paper filtering of fetching;

Constant volume: get and filter back clear liquid 10ml constant volume in the 250ml volumetric flask;

Acidifying: clear liquid adds 1: 1 hcl acidifying of 2ml after getting the 10ml constant volume in beaker;

Precipitation: after acidifying, add excess chlorination barium solution precipitation in the clear liquid;

Back titration: with sedimentation and filtration and fully washing, at PH=10, the total amount of giving instruction and filtering barium calcium ions and magnesium ions in the clear liquid of back with complexing agent EDTA titration under the condition of agent with eriochrome black T.Simultaneously by measuring the content that calcium magnesium total amount calculates sulfate radical.

Good effect of the present invention is, realized the mensuration of required index calcium magnesium total amount in the magnesium method desulfurization slurry simultaneously, also further finish the chain and fast measuring of sulfate ion, contain in this desulfuration solution in addition and make the significantly a large amount of magnesium ions of indicator discoloration, therefore do not need to dispose barium magnesium mixed liquor.Improved the accuracy that sulfate radical detects in the magnesium method desulphurization system debug process, shortened experimental period, for system stable operation provides experimental data timely.Avoided phenomenon time lag of gravimetric determination, and Instrument measuring cause than mistake.Have very strong applicability and operability.Be applicable to the fast measuring of sulfate radical content in the magnesium oxide method desulphurization system commissioning test process.

Embodiment

The method of sulfate radical content in a kind of fast measuring magnesium method sweetening process, by getting absorption tower slurries are filtered, the process of constant volume, acidifying, precipitation, back titration forms,

Filter: in the beaker of sample of fetching with qualitative filter paper filtration and 250ml;

Constant volume: get and filter back clear liquid 10ml in the volumetric flask of 250ml, shake up standby;

Acidifying: pipette in the beaker of clear liquid 10ml and 250ml behind the constant volume, add 1: 1 hydrochloric acid solution of 2ml.The inferior sulfate radical of going out stirs with glass bar, and heated and boiled is 5 minutes simultaneously, after the cooling;

Precipitation: the barium chloride solution 5ml that accurately adds excessive 0.43mol/L to cooling back solution.Filter and wash to the conical flask of 250ml;

Back titration: with concentration is the complexing agent EDTA of 0.0104mol/L, at triethanolamine is screening agent, in the ammonia buffer medium of PH=10, is indicator with the eriochrome black T, the total amount of the barium of overtitration, calcium, magnesium ion, solution colour become sky blue by claret and are terminal point.Get clear liquid 10ml direct titration calcium magnesium total amount behind the constant volume simultaneously, as blank.Thereby calculate the content of sulfate radical.

Computing formula: C (SO ₄ ^2-G/L)=[5ml * 0.43mol-C _EDTA* (V1-V2)] * 1000 * 0.4.

Claims (3)

1. the method for sulfate radical content in the fast measuring magnesium oxide method sweetening process is made up of the mensuration process of filtration, constant volume, acidifying, precipitation, back titration, is applicable to the magnesium oxide method sweetening process.

2. mensuration process in the claim 1, it is measured process feature and is:

Filter: with the sample filter paper filtering of the absorption tower slurries fetched;

Constant volume: get 10ml and filter back clear liquid constant volume in the 250ml volumetric flask;

Acidifying: clear liquid adds the watery hydrochloric acid acidifying of 1: 1 concentration after getting the 10ml constant volume in beaker;

Precipitation: after acidifying, add excessive 0.43mol/L barium chloride solution 5ml in the clear liquid;

Back titration: with sedimentation and filtration and fully washing, with concentration is the complexing agent EDTA of 0.0104mol/L, at triethanolamine is screening agent, in the ammonia buffer medium of PH=10, with the eriochrome black T is indicator, the total amount V1 of the barium of overtitration, calcium, magnesium ion, solution colour become sky blue by claret and are terminal point.Get clear liquid 10ml direct titration calcium magnesium total amount V2 behind the constant volume simultaneously.Thereby calculate the content of sulfate radical.

Computing formula: C (SO ₄ ^2-G/L)=[5ml * 0.43mol-C _EDTA* (V1-V2)] * 1000 * 0.4.

3. by adopting back titration method indirect determination sulfate radical in the claim 2, regulate volumetric soiutions PH=10 with the buffer solution of ammonia.With the eriochrome black T is indicator.