GOST 1219.4-74
GOST 1219.4−74 calcium Babbits. Method for determination of magnesium content (with Amendments No. 1, 2)
GOST 1219.4−74
Group B59
INTERSTATE STANDARD
CALCIUM BABBITS
Method for determination of magnesium content
Lead-calcium bearing alloys.
Method for determination of magnesium content
ISS 77.160.20*
AXTU 1709
____________________
* In the index «National standards» 2006
ISS
Date of introduction 1975−01−01
The decision of the State standards Committee of the Council of Ministers of the USSR from January 17, 1974 N 150 date of introduction is established 01.01.75
Limitation of actions taken by Protocol No. 2−92 of the Interstate Council for standardization, Metrology and certification (ICS 2−93)
REPLACE GOST 1219−60 in part of sec. V
EDITION (September 2003) with Changes No. 1, 2 approved in November 1979 and November 1984 (IUS 1−80, 2−85).
This standard applies to calcium babbits and sets the volume complexometric method for determination of magnesium content (with mass fraction of magnesium from 0.01 to 0.2%).
The method is based on the ability of the magnesium ion to form in alkaline conditions EDTA chelation connection with Trilon B. To set the end point of titration is used corresponding metallindustri that form with the designated colored ion complexes are less durable than the ion complex with Trilon B. At the end point of the titration with full binding in the complex ion titrated with Trilon B solution is painted in the color inherent to the free indicator. Preventing the components of alloy is removed by successive deposition of sulfate sodium, sodium diethyldithiocarbamate and ammonium oxalate.
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 1219.0−74.
2. REAGENTS AND SOLUTIONS
Nitric acid GOST 4461−77 diluted 1:4.
Sodium sulfate according to GOST 4166−76, 20% solution.
Diethyldithiocarbamate sodium GOST 8864−71, 10% solution.
Ammonia water according to GOST 3760−79, 25% solution.
Ammonium oxalate according to GOST 5712−78, 4% solution.
Ammonium chloride according to GOST 3773−72.
Sodium chloride according to GOST 4233−77.
Indicator eriochrome black T; is prepared as follows: 0.1 g of the indicator is triturated with 10 g of sodium chloride.
Buffer solution; prepared as follows: 20 g of ammonium chloride dissolved in water, add 100 cmof aqueous ammonia and diluted to 1 DM
with water.
Zinc GOST 3640−94 brand C0, 0.02 M solution; prepared as follows: first, prepare 0.1 M solution of zinc, for which a portion of the zinc to 6 538 g dissolved in 50 cmof hydrochloric acid diluted 1:1, put the solution in a volumetric flask with a capacity of 1 DM
and adjusted to the mark with water. Precise 200 cm
of 0.1 M solution of zinc is placed in a volumetric flask with a capacity of 1 DM
and adjusted to the mark with water.
Trilon B (disodium salt of ethylenediaminetetraacetic acid) according to GOST 10652−73, 0.02 M solution; prepared as follows: 8 g Trilon B dissolved in water and the volume was adjusted to 1 DM.
The installation of the titer of 0.02 M solution of Trilon B
The titer of the solution Trilon B is set at 0.02 M solution of zinc chloride. Put 20 cmof an aqueous solution of zinc chloride in conical flask, add 100 cm
of water 15 cm
buffer mixture and 0.05−0.1 g of the indicator eriochrome black So Obtained violet solution titrated with a solution of Trilon B till the transition of color in blue without the purple tint.
The titer of Trilon B (), expressed in g/cm
magnesium, calculated according to the formula
where 
0.02 M solution of Trilon, g/cm
;
— the amount of 0.02 M solution of zinc, cm
;
— the number of solution Trilon B, spent on titration, sm
.
3. ANALYSIS
A portion of the babbit 5 g, taken with an accuracy of at least 0.001 g, dissolved in 30 cmof nitric acid, diluted 1:4, when heated. At the time of the dissolution beaker cover watch glass. After dissolution of the alloy to the sample flow 40 cm
of warm water and 20 cm
of sodium sulfate with constant stirring. Provide sediment to settle for 10 min and filtered through a double filter of medium density. Precipitate was washed in the beaker and on the filter 3 times with cold water and drop. To the filtrate is added to 50 cm
of a solution of sodium diethyldithiocarbamate. The dropped sediment is allowed to settle for 10−15 minutes, and then filtered it to triple a loose filter, on which is placed a small amount of paper pulp made from ash-free filter. Precipitate was washed in the flask and on the filter 3 times with water and discarded. The filtrate was poured 50 cm
of a solution of ammonium oxalate and heated to boiling, which support 10 min then the solution was allowed to stand for 1 h, then filtered through the filter medium density, on which is placed a small quantity of paper pulp.
The filtrate and the washings collected in a conical flask with a capacity of 500 cm. Washed the flask and the filter 3−4 times with cold water (boiled). To the filtrate is added 100 cm
water 20 cm
buffer solution, 20 cm
of ammonia and 0.05−0.1 g of the indicator eriochrome black T, and then titrated with 0.02 M solution of Trilon B to a transition of a purple color in the blue. Conduct the titration immediately after adding the indicator to avoid partial decomposition.
In parallel with the analysis of the sample are control experience on all the reagents used for the determination of magnesium.
4. PROCESSING OF THE RESULTS OF THE ANALYSIS
4.1. Mass fraction of magnesium (a) in percent is calculated by the formula
where a titer of 0.02 M solution of Trilon B, expressed in g/cm
magnesium;
— the amount of 0,02 M Trilon B solution, consumed for titration of sample solution, cm
;
— the amount of 0,02 M Trilon B solution, consumed for titration of the solution in the reference experiment, cm
;
— hanging Babbitt, g
.
4.2. Allowable absolute differences between the extreme results of the analysis shall not exceed 0,0015% when the mass fraction of magnesium from 0.01 to 0.03% and 0.003% for the mass concentration of magnesium in excess of 0.03−0.07%, 0,005%, with mass fraction of magnesium from 0.07 to 0.2%.
(Changed edition, Rev. N 1, 2).
