1、 FORD LABORATORY TEST METHOD AK 112-01 Date Action Revisions 2001 01 22 Revised Editorial no technical change A. Cockman 2000 03 23 Revised Editorial no technical change A. Cockman 1990 06 12 Printed copies are uncontrolled Page 1 of 4 Copyright 2001, Ford Global Technologies, Inc. QUANTITATIVE ANAL
2、YSIS OF SILICATES IN CLEANERS Application This test method is used to determine the percent silicates in a cleaner. The procedure is intended to be a simplified version of the applicable ASTM standard (e.g., D 501 or D 800) as well as being more appropriate for dealing with the many formulations of
3、cleaners that are commonly encountered in plant operations. Apparatus Required Muffle Furnace Capable of maintaining 760 +/- 10 C. Oven Mechanical convection; capable of maintaining 105 - 110 C. Hot Plate Bunsen or Meker Burner Analytical Balance Precision +/- 1 mg. Desiccator With drying compound.
4、Crucible Suitable for holding filter paper. Pipet Tongs Funnel Suitable for use with filter paper. Beaker 250 mL Watch Glass and Glass Hooks Suitable for use with 250 mL beaker. FORD LABORATORY TEST METHOD AK 112-01 Page 2 of 4 Copyright 2001, Ford Global Technologies, Inc. Graduated Cylinder 100 mL
5、 Platinum Crucible Materials Required Sulfuric Acid Concentrated; CAUTION: Corrosive Nitric Acid Concentrated; CAUTION: Corrosive Hydrofluoric Acid Concentrated; CAUTION: EXTREMELY CORROSIVE - SPECIAL HANDLING PRECAUTIONS MUST BE EMPLOYED. Distilled Water or Deionized Water 10 ppm max total dissolve
6、d solids (ASTM D 1888). Filter Paper Whatman No. 42. Solutions Required Sulfuric Acid Solution 1:1 Hydrochloric Acid Solution 1:1 Hydrochloric Acid Solution 5 mL HCl/95 mL distilled water. Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a contro
7、lled atmosphere of 23 +/- 2 C and 50 +/- 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditions unless otherwise specified. FORD LABORATORY TEST METHOD AK 112-01 Page 3 of 4 Copyright 2001, Ford Global Technologies, Inc. Procedure 1. Take a 0.5 to 1.0 g al
8、iquot of the prepared 1 % solution in a 400 mL beaker. 2. Dilute with 50 mL of distilled water. 3. Add 20 to 25 mL of 1:1 sulfuric acid. 4. Cover the beaker with a watch glass. Support the cover glass on glass hooks to facilitate evaporation. 5. Place the beaker on the hot plate and evaporate to cop
9、ious fumes of sulfuric acid. 6. Very carefully introduce concentrated nitric acid into the beaker drop-wise using a pipet. 7. Swirl beaker using tongs for dispersion throughout the fuming solution. 8. Continue adding the nitric acid until the solution appears water white. 9. Let beaker continue evap
10、orating on the hot plate until the residue becomes dry. 10. Examine for discoloration. If the residue appears to be discolored, organic matter is still present. 11. If this occurs, cool the beaker and contents, add 5 to 10 mL of 1:1 sulfuric acid and repeat the above starting from step 5. 12. When t
11、he contents of the beaker, after drying, appear to be white in color, bake the beaker and contents for 4 h on the hot plate. 13. Cool the beaker and its contents. 14. Add 10 to 20 mL of 1:1 hydrochloric acid to the beaker and moisten the contents. Heat on hot plate for 5 minutes. A. The dehydrated s
12、ilica along with mass of other materials must not be treated first with water since hydrolysis causes the formation of insoluble matter containing iron and aluminum. B. 1:1 hydrochloric acid in minimum amount should be used first to wet the dehydrated silica and should be followed by distilled water
13、 to bring the volume to about 100 mL, after which the silica should be filtered off as quickly as possible. 15. Add 100 mL of distilled water. 16. Heat to boiling and remove from hot plate. FORD LABORATORY TEST METHOD AK 112-01 Page 4 of 4 Copyright 2001, Ford Global Technologies, Inc. 17. Allow ins
14、oluble matter to settle. 18. Filter through No. 42 Whatman filter paper. 19. Police beaker to remove any residue that remains. 20. Wash using a hot solution consisting of 5 mL of hydrochloric acid to 95 mL of distilled water. 21. Finally wash with hot distilled water. 22. The filter paper and conten
15、ts are placed in a tared crucible. 23. Dry this crucible at 105 - 110 C. 24. Gently heat the crucible until the filter paper is charred using a Bunsen or Meker burner. 25. Ignite more strongly to destroy the filter carbon with the burner. 26. Finally place in a muffle furnace at 760 C for 30 minutes
16、. 27. Cool in a desiccator and reweigh. 28. Repeat ignition to constant weight. Note: A. For many practical purposes this residue is accepted as silica unless it is highly colored. For more accurate work especially where contamination is suspected (silica should be white), this residue is treated fu
17、rther. B. The weighed residue is treated with 3 mL of distilled water, followed by several drops of concentrated sulfuric acid and 5 mL of hydrofluoric acid (HF) in the hood. After evaporation to dryness, the crucible is heated to redness again, cooled and weighed. The loss of weight represents sili
18、ca, SiO2. A platinum crucible must be used for this. Calculate the percent of SiO2 Wt of Residue after Ignition x 100 = SiO 2 Wt of Sample % of SiO2 x 2.0316 = % Sodium Metasillicate (Na2SiO3) Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities.
