Applied Chemistry

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CONCISE PROCESS DESCRIPTION OF THE BATCH BENCH SCALE PHOSPHOROUS PENTAFLUORDIE AND LITHIUM HEXAFLUOROPHPOSPHATE PILOT PLANTS

DOC NO: AC-LIPF6TECH-DES-20006

Revision: 1

Author: HF Niemand and I Govender

24 August 2020

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Applied Chemistry

TABLE OF CONTENTS

1 Purpose and Scope ...... 3 2 CONCISE PROCESS DESCRIPTION OF THE BATCH BENCH SCALE PHOSPHOROUS PENTAFLUORIDE PILOT PLANT ...... 3 2.1 BLOCK FLOW DIAGRAM...... 3 2.2 PROCESS DESCRIPTION ...... 3 3 CONCISE PROCESS DESCRIPTION OF THE BATCH BENCH SCALE LITHIUM PILOT PLANT ...... 4 3.1 BLOCK FLOW DIAGRAM...... 4 3.2 PROCESS DESCRIPTION ...... 4

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Applied Chemistry

1 Purpose and Scope This document contains a concise process description for a batch bench scale pilot plant for the production of lithium hexafluorophosphate. The pilot plant consists of two sections: (1) The reaction of pentoxide, sodium and anhydrous to produce phosphorous pentafluoride, and (2) the reaction of phosphorous pentafluoride from the first section with to form lithium hexafluorophosphate.

2 CONCISE PROCESS DESCRIPTION OF THE BATCH BENCH SCALE PHOSPHOROUS PENTAFLUORIDE PILOT PLANT

2.1 BLOCK FLOW DIAGRAM

Phosphorus pentoxide

Anhydrous Phosphorus hydrogen fluoride pentafluoride to lithium Dissolution Reaction Crystallization Filtration Drying Decomposition Sodium hexafluoro fluoride pilot plant

Sodium fluoride

Recovered hydrogen fluoride Distillation

Recovered sodium acid fluoride liquor Aqueous Evaporation hydrogen fluoride 2.2 PROCESS DESCRIPTION The process is a batch process.  is dissolved in an excess of anhydrous hydrogen fluoride.  The solution reacts with phosphorous pentoxide to form sodium hexafluoro phosphate.  After evaporation of some of the excess hydrogen fluoride, the sodium hexafluoro phosphate is crystallized and the crystals are separated from the liquor by filtration.  The crystals are dried at an elevated temperature.  The dry crystals are decomposed at an elevated temperature to form phosphorous pentafluoride gas and sodium fluoride. The sodium fluoride is recycled for dissolution. The phosphorous pentafluoride gas is captured by freezing, thawed and stored for usage by the lithium hexafluoro phosphate pilot plant.  The filtrate from the filter is distilled to recover most of the excess hydrogen fluoride. The recovered hydrogen fluoride is recycled to the dissolution reactor.  The excess water in the bottom product is evaporated and the remaining sodium acid fluoride liquor is recycled to the dissolution reactor. AC-LIPF6TECH-DES-20006 Rev: 1 Page 3 of 4

Last printed 2020/12/14 12:15:00 OPEN

Applied Chemistry

3 CONCISE PROCESS DESCRIPTION OF THE BATCH BENCH SCALE LITHIUM HEXAFLUOROPHOSPHATE PILOT PLANT

3.1 BLOCK FLOW DIAGRAM

Phosphorous pentafluoride

Anhydrous Hydrogen fluoride Lithium Dissolution Reaction Crystallization Filtration Drying Lithium fluoride hexafluorophosphate

Recovered hydrogen fluoride

3.2 PROCESS DESCRIPTION The process is a batch process.  Lithium fluoride is dissolved in an excess of anhydrous hydrogen fluoride.  The solution reacts with to form lithium hexafluorophosphate.  The lithium hexafluorophosphate is crystallized and the crystals are separated from the liquor by filtration.  The crystals are dried at an elevated temperature.  The filtrate from the filter is recycled to the dissolution reactor.

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