Trilithium hexafluoroaluminate

Melting point / freezing point

Link to relevant study record(s)

Reference

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 20 September 2013 (date of the measurement) to 06 November 2013 (date of the test report)

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

GLP compliance:

no

Other quality assurance:

other: laboratory certified according to ISO/TS 16949

Type of method:

thermal analysis

Key result

Melting / freezing pt.:

> 600 °C

Decomposition:

yes

Decomp. temp.:

> 600 °C

No precise melting point was determined. The substance decomposes at temperatures above 600°C, with a significant weight loss related to an endothermic peak at 610°C, followed by a roughly constant decrease of the head flow rate.

The measurement shows a slight endothermic behavior in the temperature range from approximately 30°C to approximately 400 °C related with a moderate weight loss of around 2.1%. This is most likely due to loss of water coming from the physically adsorbed humidity and the decomposition of possible impurities (crystallisation water, hydrates).

At 428°C and 473°C (Peak Onset) two endothermic enthalpy peaks are measured. Due to the thermal flow behavior it is considered that these peaks relate to a solid-solid phase transition of the crystal structure.

At a temperature above 600°C a significant weight loss is seen in conjunction with an endothermic enthalpy peak at 602°C (Onset peak) followed by a roughly constant decrease of the heat flow rate. It is assumed that Li3AlF6 will melt under decomposition at temperatures above 600°C.

Conclusions:

It is assumed that Li3AlF6 will melt under decomposition at temperatures above 600°C.

Executive summary:

In this study the melting point of Lithium cryolite has been measured by a Differential Thermal Analysis (DTA) combined with a Thermal Gravimetry (TG) in accordance with the OECD Testing Guideline 102.

No precise melting point was determined. The substance decomposes at temperatures above 600°C, with a significant weight loss related to an endothermic peak at 610°C, followed by a roughly constant decrease of the head flow rate.

It is assumed that Li3AlF6 will melt under decomposition at temperatures above 600°C.

Description of key information

Li3AlF6 melts under decomposition at temperatures above 600°C.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

600 °C

Additional information

One reliable key study is available for this endpoint. In this study the melting point of Lithium cryolite has been measured by a Differential Thermal Analysis (DTA) combined with a Thermal Gravimetry (TG) in accordance with the OECD Testing Guideline 102.

No precise melting point was determined. The substance decomposes at temperatures above 600°C, with a significant weight loss related to an endothermic peak at 610°C, followed by a roughly constant decrease of the head flow rate.