Infrared Combustion Sulfur Analyzer for Coal

What is the Infrared Combustion Sulfur Analyzer for Coal?

An infrared combustion sulfur analyzer burns coal or coke in oxygen and measures the sulfur dioxide produced with a non-dispersive infrared cell. It covers a wide sulfur range quickly and is the routine choice in many commercial laboratories.

Overview

A weighed sample in a ceramic crucible is combusted in a stream of oxygen in an induction or resistance furnace at 1350 °C or above. The combustion gases pass through a dust and moisture trap to a non-dispersive infrared cell tuned to the sulfur dioxide absorption band, and the integrated signal over the combustion period gives the sulfur mass. Carbon and moisture traps prevent interference from other combustion products. Calibration is performed with certified reference coals, and stability is monitored with a sample of known sulfur. Instruments of this type usually accept larger sample masses than coulometric units, can also be configured for carbon and hydrogen, and are well suited to a wide range of ranks, provided the furnace temperature and oxygen flow are sufficient for complete combustion of slow-burning cokes.

How does it work?

Sulfur in coal occurs as sulfate, pyritic sulfide and organic compounds, and total sulfur is normally determined after complete combustion. A weighed sample is burned in oxygen at about 1350 °C in a tube furnace, converting sulfur to sulfur dioxide and trioxide. In an infrared analyzer the gas passes through a cell and its absorption of infrared light is quantified against a calibration from reference coals. In a coulometric titrator the gas is absorbed in an electrolyte and sulfur is titrated electrolytically, with the titration current integrated to give the mass of sulfur. Classical Eschka and bomb-washing procedures dissolve the sulfur and finish by gravimetric or acidimetric titration. X-ray fluorescence estimates sulfur from the sulfur peak intensity against matrix calibrations, and on-line prompt gamma neutron activation units irradiate the whole coal stream and count gamma rays emitted by sulfur nuclei. Results are reported on as-received, dry or dry ash-free basis.

What are the key features?

• Resistance or induction furnace above 1350 °C
• Non-dispersive infrared sulfur dioxide detector
• Dust, moisture and halogen traps on the gas path
• Calibration with certified reference coals
• Optional carbon and hydrogen measurement channels
• Automatic crucible feeding on carousel models

What are the technical specifications?

A typical infrared combustion sulfur analyzer for coal configuration offers sulfur measurement range of 0.01–100 % depending on calibration, furnace temperature of 1350–1500 °C, analysis time of 2–5 min per sample, sample mass of 0.1–0.5 g, detector of NDIR sulfur dioxide cell and repeatability of Within ASTM D4239 limits. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Infrared Combustion Sulfur Analyzer for Coal is used in commercial coal laboratory sulfur analysis, coke sulfur determination for steelmaking, coal preparation plant quality control and research on coal desulfurization. Across the wider Sulfur Analyzers class, laboratories also deploy it for contract sulfur limit verification for coal shipments, power station SO2 emission control and coal preparation plant desulfurization control.

Which standards and certifications apply?

Relevant standards and methods include ASTM D4239, ASTM D3177, ASTM D5016, ISO 351, ISO 334, ISO 19579, GB/T 214, ASTM D4326 and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Place combustion sulfur analyzers under an extraction hood and provide dry, oil-free oxygen at the required purity and pressure, since moisture and hydrocarbons disturb the detector. Set the furnace temperature and check it with a calibrated thermocouple, because low temperature leaves sulfur unvolatilized and biases results low. Condition and replace the catalyst, reagent and filters on the schedule given for your sample load, and verify performance daily with a reference coal that brackets your working range. Keep an up-to-date calibration from coals of similar rank, and recheck after any hardware change. For XRF and neutron analyzers, document the calibration model and radiation licensing, and compare results with the combustion reference method at defined intervals. Record the reporting basis for every result.

How do I select the right Infrared Combustion Sulfur Analyzer for Coal?

Select the infrared combustion analyzer for a broad sulfur range, larger sample masses and high throughput, particularly if you also want carbon or hydrogen channels. Confirm the furnace temperature is adequate for your coke or low-volatile samples, and specify crucible carousel size, gas supplies and reference materials.

How does it compare with other Sulfur Analyzers variants?

Start from the method named in your contract and from the sulfur level you must resolve, because repeatability becomes critical near regulatory limits such as 0.5 % or 1 % sulfur. Infrared combustion instruments are the most common choice for routine coal analysis: they are fast, cover a wide range and use reference coal calibrations. Coulometric titration analyzers are widely used in Chinese and other national laboratories, are economical and reach low detection limits, but need careful electrolyte management. Acidimetric titration equipment remains the classical route for coke and for laboratories that prefer a wet-chemical finish. X-ray fluorescence gives near-instant screening and combines sulfur with ash reporting, but is a secondary method. On-line neutron activation suits blending and washing control where whole-stream data are more useful than spot samples, though licensing applies.