Spectrophotometric determination of phosphorous in ferro alloys, manganese ore and iron ore

Introduction

Phosphorus is a hazardous impurity (poison) in steel. Steel with high phosphorus content becomes extremely brittle at a low temperature, and the mechanical properties of steel exhibit worsening impact strength and elongation abruptly decrease. Therefore, for obtaining low-phosphorous manganese-containing steels, it is necessary to have manganese ferroalloys with the lowest possible phosphorus content. The production of such manganese ferroalloys is possible in the presence of low-phosphorus ores and concentrates rich in manganese. In the case of poor manganese ores with increased phosphorus content, after ore-dressing, it is necessary to introduce an additional process stage such as dephosphorization of manganese concentrates, and then to smelt manganese ferroalloys based on the obtained concentration. So knowledge of phosphorous content in raw materials of steel is very important.

Spectrophotometric method for determination of phosphorous involves various reducing agents, for example, ascorbic acid, stannous chloride, mixture of hydrazine sulfate and sodium sulfide. A few of these methods require complicated and expensive equipments and few of them also involve complicated extraction procedures limiting the practice of such methods in common laboratories. In this background we have tried to develop a simple and straight forward spectrophotometric method for phosphorous determination with a reducing agent, hydroxyl ammonium chloride. Hydroxyl ammonium chloride is commercially available, economically cheaper, known for good shelf stability and already used as a reducing agent in phosphorous determination by other method. An official phosphomolybdate method involving ascorbic acid has a limitation associated with the latter’s stability that prompted us to consider hydroxyl ammonium chloride as a reducing agent. In the present method, hydroxyl ammonium chloride is used to reduce the phosphomolybdate formed in acidic medium from the test quantity of phosphorous and the concentration of reduced phosphomolybdate is measured from the absorbance at 825 nm. The developed method is used effectively for the determination of phosphorous present in the samples of iron ores, manganese ore, silico manganese, ferro manganese. The results of phosphorous determined from the new method involving heteropoly acid are in good agreement with the results of phosphorous determined separately from the method involving ICP-OES.

Experimental

After dissolution of samples (Mn Ore, Iron Ore, Silico manganese and Ferro manganese) filter off the silica. Transfer a suitable aliquot of the solution in two 100 ml volumetric flasks, add to each flask iron (III) chloride solution and ammonia solution until the first appearance of an iron (III) hydroxide precipitate. Add HCl dropwise until the precipitate is dissolved. Add hydroxylammonium chloride solution, heat the solutions to boiling to decolorize them. Allow the solutions to cool to 25 ℃ and add HCl (1:1) to both the flasks but add ammonium molybdate solution to one of the two volumetric flasks.

Photometric measurement

Allow the solutions to stand for 10 min in order to develop the colour. Measure the absorbance of the test solution using the spectrophotometer at 825 nm, against the solution containing no ammonium molybdate as reference.

Blank test

Carry out the blank test through all stages of the analysis.

Calibration curve

Results

We have analysed several number of samples of different commodities

Sample No

Commodity

%P in ICP

%P using spectrophotometer

Difference

28616 (CRM

SiMn

0.205

0.203

0.002

SiMn

0.150

0.168

-0.018

SiMn

0.230

0.246

-0.016

SiMn

0.300

0.317

-0.017

SiMn

0.142

0.130

0.012

FeMn

0.165

0.161

0.004

FeMn

0.169

0.155

0.014

FeMn

0.162

0.159

0.003

LCSiMn

0.163

0.152

0.011

LCSiMn

0.188

0.172

0.016

JK 28(CRM)

Iron Ore

0.045

0.043

0.002

PI 3.2

Iron Ore

0.022

0.020

0.002

682-2

Iron Ore

0.053

0.055

-0.002

176-4

Mn ore

0.058

0.055

0.003

NCS DC 28041

Mn ore

0.011

0.012

-0.001

SARM 16

Mn ore

0.033

0.034

0.001

Conclusion

The optimized method for the spectrophotometric determination of phosphorous is working on simple and straight forward principles of reducing phosphomolybdate complex formed from test quantity of phosphorous and molybdate in excess followed by its reduction with hydroxylammonium chloride solution leading to the formation of molybdenum blue which could be monitored at 825 nm. Chemicals involved in the method are cheap and are considered to be normally available in common laboratories. The method is unlike other methods since it neither involves sophisticated instruments like ICP-OES nor requires strict control of pH. The reducing agent, hydroxylammonium chloride employed here to reduce phosphomolybdate is a known shelf stable and preservative and preparation of its solution is also simple and solution once prepared it is found to be very stable when compared to the nature and stability of ascorbic acid solution which is used as a reducing agent for phosphomolybdate to determine phosphorous in an official method. In that official method the reducing agent ascorbic acid solution is to be prepared on daily basis. In addition, the developed new method is working satisfactorily for the determination of phosphorous present in various samples analyzed here. The phosphorous results obtained using the new method are in good agreement to that obtained using ICP-OES. Therefore, the developed new spectrophotometric method with reducing agent hydroxylammonium chloride for the determination of phosphorous can be used either as an independent or as an alternate method to the existing instrumental method. This method is also less time consuming than wet chemical method.

Contributed by Ms. Alakta Saha under the guidance of Prof. Barun K. Gupta.

Testimonial

Mitra S.K. have added value to our business process by effective inspection, strict quality control and timely response. It is a pleasant experience to work with “Team Mitra S.K.”. We hope the same service level will continue in the future too....

Sirsendu Mukherjee

Chief Operation, FAMD, Tata Steel Limited..

Mitra SK Inspection Gulf LLC has been appointed by us and the services provided by them has been up to the mark and as per our expectations....

Ajay Mathur

Sr. General Manager,, Emirates Trading Agency L.L.C..

Mitra S. K. Private Limited is skilled in analysis and laboratory working. They understand operating requirements. They bring a winning combination of experience and commitment to excellence. During our rigorous selection process, Mitra S. K. showed us their flexibility and significant capabilities in testing and supervision field. They have deep understanding of the testing, strong customer care capabilities and their global delivery footprints....

Amar Singh Gohil

Mines Manager, Hindustan Zinc Limited, a Vedanta Company.

The Inspection services provided by Mitra S. K. Inspection Gulf has been prompt and accurate and has been in the line with our expectations....

Naser Bustami

General Manager, Stevin Rock L.L.C..

We would like to express our high appreciation of the business association our company had with Mitra S. K. as a testing and inspection house for their quality of service, good documentation and reporting during the job ....

R. Jeyakumar

Executive Vice President (Works),, DCW Limited.

We would like to express our high appreciation for PT Mitra S.K. Analisa Testama as a professional and reliable Testing and Inspection house for their quality services rendered which currently differentiates them from their competitors. they we selected by us due to high quality of services, accurate results, fast response, full support to give documentation and reporting of detail condition during the job....

Tulus Situmeang

AVP – Coal Quality & Sales Compliance Head,, PT Indo Tambangraya Megah Tbk (BANPU).

Their job was excellent and showed Mitra S.K. differential from others....

Geraldo Pimenta

Laboratory Head, MMX.

Mount Gibson engaged Mitra S.K. Private Limited (Mitra S.K.) in mid-2013 to observe and inspect the procedures for unloading of iron ore from vessels in Chinese ports, and the sampling of the ore. Mitra S.K. personnel have since that time overseen numerous shipment movements and cargo discharges, and provided reports thereon. We have found the service offered by Mitra S.K. to be very reliable and professional, with reports being timely and informative.....

Konstantin Gertsen

Shipping Administrator, Mount Gibson Iron Limited.

We’ve been pleased with the improvement we have seen in CIQ results, and Mitra S.K’s reports have certainly helped us to resolve any disputes with our customers in a more timely manner….....

Brian Mcdonald

Senior Director – Asia Pacific Iron Ore Sales,, Cliffs Natural Resources Pty Ltd..

Write to Us

LATEST blog

Mineral Beneficiation and Upgradation

Posted on December 03 2024 By Mitra S.K ADMIN

What if your old PCBs (Printed Circuit Boards) hold untapped Treasure?

Posted on October 17 2024 By Mitra S.K ADMIN

Per- and polyfluoroalkyl substances (PFAS), commonly referred to as "forever chemicals," have emerged as a significant environmental and health concern

Posted on October 04 2024 By Mitra S.K ADMIN

If Your Starch Helping or Holding You Back?

Are your mineral transportation operations hindered by freezing in cold climates? Wondering how MSK tackled this challenge?

Posted on April 30 2024 By Mitra S.K ADMIN

Understanding the Impact of Indirect Greenhouse Gases on Global Warming

Investigation of Physico-chemical properties of Refined Palm oil during frying with special reference to in vitro lipid peroxidation as TBARS

Posted on November 28 2022 By Mitra S.K ADMIN

Spectrophotometric determination of phosphorous in ferro alloys, manganese ore and iron ore

Testimonial

Mitra S.K. have added value to our business process by effective inspection, strict quality control and timely response. It is a pleasant experience to work with “Team Mitra S.K.”. We hope the same service level will continue in the future too....

Sirsendu Mukherjee

Mitra SK Inspection Gulf LLC has been appointed by us and the services provided by them has been up to the mark and as per our expectations....

Ajay Mathur

Amar Singh Gohil

The Inspection services provided by Mitra S. K. Inspection Gulf has been prompt and accurate and has been in the line with our expectations....

Naser Bustami

We would like to express our high appreciation of the business association our company had with Mitra S. K. as a testing and inspection house for their quality of service, good documentation and reporting during the job ....

R. Jeyakumar

Tulus Situmeang

Their job was excellent and showed Mitra S.K. differential from others....

Geraldo Pimenta

Konstantin Gertsen

We’ve been pleased with the improvement we have seen in CIQ results, and Mitra S.K’s reports have certainly helped us to resolve any disputes with our customers in a more timely manner….....

Brian Mcdonald

Write to Us

LATEST blog

Mineral Beneficiation and Upgradation

What if your old PCBs (Printed Circuit Boards) hold untapped Treasure?

Per- and polyfluoroalkyl substances (PFAS), commonly referred to as "forever chemicals," have emerged as a significant environmental and health concern

If Your Starch Helping or Holding You Back?

Understanding PM100 in Mining Activities

Unlocking the Potential of Spent Grain: A Sustainable Approach

Spot Emission Measurement

Opacity Meters

Effluent Treatment Plant

Baseline study in E I A process

Performance guarantee and performance evaluation

Terrestrial Flora and Fauna

Aquatic Flora and Fauna

Mineralogy of Manganese Ore: Beneficiation and Beyond: MSK's Solution to African Mine

Are your mineral transportation operations hindered by freezing in cold climates? Wondering how MSK tackled this challenge?

Understanding the Impact of Indirect Greenhouse Gases on Global Warming

Phase transformation of silica in Coal and Biomass burning processes and its implications on human health

MODIFIED GRAVIMETRIC ESTIMATION OF COBALT IN BLACK MASS

Method development for the estimation of Coumarin content in different Cinnamomum species

Rapid determination of Tyramine and Histamine in Tuna Fish using HPLC-FLD

MICROPLASTIC IN MILK. AN EMERGING THREAT

Estimation of Proline in Honey by High Performance Liquid Chromatography

DNA based approach for the detection of GMO

Development of an HPLC-FLD method for rapid determination of Tyramine and Histamine in Tuna Fish

Determination of Acrylic acid emissions from industrial process by HPLC

COMPARATIVE STUDY OF NANO-FERTILIZER & CONVENTIONAL FERTILIZER WITH RESPECT TO SUSTAINED NUTRIENT RELEASE

Assessing leaching potential of Electronic Waste

Analysis of Red Mud

Determination of gold using ICP-OES after activated carbon enrichment

Determination of platinum group metals using nickel sulfide (NiS) fire assay

QUANTIFICATION OF POTASSIUM IN NPK FERTILIZER BY GRAVIMETRY

Rapid Phase Composition Study of Portland cement-Clinker by Powder X-ray Diffraction Technique and its Impact

Recycling of lead acid batteries

Spectrophotometric determination of phosphorous in ferro alloys, manganese ore and iron ore

A Novel Technique to Identify Mineral Oil Contaminants in Vegetable Oil

Alpha amylase enzyme activity of various grains with special reference to sprouting

A degradation study of beta carotene in infant food and raw vegetables by ozone treatment

Environmental impacts of firecrackers during festivals, events - a lab study

Spectrophotometric determination of Anthocyanin Content in Different Fresh Fruits

EXTRACTION AND ISOLATION OF PIPERINE FROM BLACK PEPPER

Investigation of Physico-chemical properties of Refined Palm oil during frying with special reference to in vitro lipid peroxidation as TBARS

Nitrogen Profile in Fertilizer by IR Absorption Spectroscopy

Protein Digestibility Corrected Amino Acid Score (PDCAAS)- A method to evaluate quality of protein

Determination of Organic carbon and Inorganic carbon of Biomass

Analysis of Anti-Nutritional Factors of Wine

Determination of Ozone Generation Efficiency of UV Lamp by Chemical Method

Our clients