headerdrawing1.jpg (96365 bytes)

Sulphuric Acid on the WebTM Technical Manual DKL Engineering, Inc.

Knowledge for the Sulphuric Acid Industry Line.jpg (1139 bytes)

Sulphuric Acid on the Web

Introduction
General
Equipment Suppliers
Contractor

Instrumentation
Industry News
Maintenance
Acid Traders
Organizations
Fabricators
Conferences

Used Plants
Intellectual Propoerty
Acid Plant Database
Market Information
Library

Technical Manual

Introduction
General

Definitions
Instrumentation
Plant Safety
Metallurgial Processes
Metallurgical
Sulphur Burning
Acid Regeneration
Lead Chamber
Technology
Gas Cleaning
Contact
Strong Acid
Acid Storage
Loading/Unloading

Transportation
Sulphur Systems
Liquid SO2
Boiler Feed Water
Steam Systems

Cooling Water
Effluent Treatment
Utilities
Construction
Maintenance
Inspection
Analytical Procedures
Materials of Construction
Corrosion
Properties
Vendor Data

DKL Engineering, Inc.

Handbook of Sulphuric Acid Manufacturing
Order Form
Preface
Contents
Feedback

Sulphuric Acid Decolourization
Order Form
Preface
Table of Contents

Process Engineering Data Sheets - PEDS
Order Form
Table of Contents

Introduction

Bibliography of Sulphuric Acid Technology
Order Form

Preface
Contents

Sulphuric Acid Plant Specifications
 

Google Search new2.gif (111 bytes)

 

 


Analytical Procedures - Fluorine in Gas Exit Drying Tower
December 19, 2002

Introduction
Equipment
Reagents
Procedure

Calculation
Associated Links

Introduction

A fluorine selective electrode allows fluorine in aqueous solution to be measured quickly, and accurately.  The electrode consists of a single-crystal lanthanum fluorine membrane, and an internal reference, bonded into an epoxy body.   The crystal is an ionic conductor in which only fluorine ions are mobile.   When the membrane is in contact with a fluorine solution, an electrode potential develops across the membrane.  This potential, which depends on the level of free fluorine ions in solution, is measured against an external constant reference potential with a digital pH/mV meter or specific ion meter.  The measured potential corresponding to the level of fluorine ions in solution is described by the Nernst equation.  Samples should be at the same temperature as standard solution. A 1°C difference in temperature will give about a 2% of measurement error.

This technique can be used also in the determination of fluorine (as HF) in a gas stream. The gas is passed through an absorption apparatus where fluorine is selectively absorbed over an alkaline solution, then the solution is measured to determine fluorine content and the result is related to the volume of the gas washed.

Equipment

Reagents

 

Procedure

Preparation of Low Level TISAB Solution

Place about 500 ml distilled water in a 1000 ml beaker.  Add 57 ml of glacial acetic acid and 58 grams of sodium chloride.   Place the beaker in a water bath for cooling and immerse a calibrated pH electrode into the solution.  Slowly add 5 M NaOH until the pH is between 5.0 to 5.5.   Cool to room temperature.  Pour into a 1 litre volumetric flask and dilute to mark with distilled water.  It is essential that all reagents used  be as pure as possible to keep the fluorine level in the buffer low.

Sampling

In the isokinetic sampling apparatus set up four impingers containing a total of 1 litre of NaOH 1 N solution after the filter membrane.  Draw about 100 litres of gas through the apparatus at a flow rate of 5 litres per minute allowing the gas to bubble through the solution.  Gather all the solution together for analysis.

Calibraton Curve

Prepare 0.25, 0.5, 1, and 2 ppm fluorine standards by serial dilution of the 100 ppm standard.  Add 50 ml TISAB, to each 50 ml standard.  Insert the probe and record the reading for each standard.  Use the data to plot a calibration curve.

Analysis

Draw about 50 ml of the collected solution, adding the same quantity of TISAB low level solution.  Before adding TISAB solution to the sample, if necessary, adjust pH to 5-6 with acetic acid 4 M.  Insert the probe and record the reading.  The fluorine concentration can be determined from the calibration curve.

Calculation

None

TopofPage.jpg (2219 bytes)