No registration or passwords; no pop-up ads -- just aloha, fun, & answers.
(as an eBay Partner & Amazon Affiliate earns from qualifying purchases).
Home /
T.O.C.
Fun
FAQs
Good
Books
Ref.
Libr.
Advertise
 
Help
Wanted
Current
Q&A's
Site 🔍
Search
pub  Where the
world gathers for metal finishing
Q&As since 1989



-----

Nitric HF acid





I would like to know about the potential uses for spent Nitric-HF acid (6:1 Ratio) which is an acid mix typically used to etch silicon wafers for the production of microchips. What industries or companies can use spent Nitric-HF acid?

Tom Mackey
- Theodore, Alabama
2000


The Si etching reaction can be expressed as follows: Si + 4HNO3 + 6HF --> H2SiF6 + 4NO2 + 4H2O Silicon is oxidized by rthe nitric acid and the resulting silicon oxide is dissolved by the HF acid.

Hexafluorosilicate and water are generated in the solution. The NO2 is gasified and treated. One possible use for the spent acid is fertilizer, but many fertilizer producers cannot handle the residual HF.

Tom Mackey
- Theodore, AL.
2000




(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

 
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g, Train'g
& Software


About/Contact  -  Privacy Policy  -  ©1995-2024 finishing.com, Pine Beach, New Jersey, USA  -  about "affil links"