SU901316A1 - Flux for smelting silver and silver-based alloys - Google Patents

Description

This invention relates to the metallurgy of noble metals. The closest to the present invention is the flux for melting silver and alloys based on it, containing sodium fluoride and boric anhydride 1. The disadvantages of the known flux are the low plastic characteristics of the resulting product and the high losses of silver and alloying fusible elements. The purpose of this is to increase the plastic characteristics of the resulting product and to reduce the loss of sulfur and alloying fusible elements. This goal is achieved in that the flux for smelting silver and alloys based on it, containing sodium fluoride and boric anhydride, additionally contains calcium fluoride and fluorine. Read aluminum in the following ratio. components, wt.%: Sodium fluoride 25-35 Boric anhydride. 15-25 Calcium fluoride 10-20 Alymini fluoride Else Example. Prepare a mixture of fluxes, the composition of which is given in Table I. Table 1 Fluoride nat 20 2530 35 40 ri Boron an10 1520 25 30 hydride. Calorium fluoride / 5 101520 20 qi Fluoride alu 50, 35 20 10 mini Components of fluxes, hang in accordance with g; "listed in Table. 1 ratio, mix thoroughly (with the exception of boric anhydride) and fall asleep in graphite Ti 3901316

gel (graphite brand GMZ) high-frequency setting MGP-102.

As the three components of the charge melt, boric angndride is introduced in parts. The readiness of the melt is monitored by sampling the tungsten rod visually. The full transparency of the melt and the easy separation from the tungsten rod of a homogeneous hardened crust indicate its readiness. Molten flux poured

in a water-cooled mold made of stainless steel H18N9T. After complete

After cooling, the flux is removed from the molds and its crushing is carried out on the disk eraser.

In order to determine the technological properties of the produced fluxes, experimental melting of the silver-based alloy (copper 5%, zinc 5%, cadmium 5%, silver else) was carried out using the fluxes of the proposed and known compositions.

The manufacturability of the flux is assessed by the quality of the ingot surface, frit of silver, zinc and cadmium, the output of a suitable metal.

The results of the experimental heats are given in table. 2

table 2

The data on the silver, zinc, and cadmium carbon monoxide are given by the results of five tests. With the use of fluxes 2, 3, 4 and the known flux, the composition of which is given in table. 1, four alloy stems are melted

0.08

1.1

2.6

91.0

0.04

0.3

1.2 silver (zinc, cadmium, copper else) weighing 1.5 kg each. Resush, tats of the research are given in table. 3. T a b i c a 3

30.0

35.0 JlT Зб.о The cleaner (tab. 3) shows the results of testing the cast metal of the upper part of the ingots, in the denominator - the bottom. The use of flux consisting,%: sodium fluoride 25-35; boric anhydride 15-25; calcium fluoride 10-20; the rest of aluminum fluoride, when refining smelting of silver and alloys based on it, produces dense metal ingots with a chorus lateral surface with no defects of metallurgical origin in them, the absence of non-metallic inclusions in the metal, high purity of metallic impurities, uniform distribution of alloying elements in ingot metal, low carbon silver and alloying elements, high technological plasticity of ingot metal; high yield (95-97%) Electricity consumption is 0.3 0, 4 kWh per 1 kg of smelted metal.

G; 7

0.6

0.07

Claims (1)

93.0 flux consumption - 5-6 kg per 1 ton of metal to be melted. Claims of the invention Flux for melting silver and alloys based on it, containing sodium fluoride and boric anhydride, characterized in that, in order to increase the plastic characteristics of the product obtained and reduce silver losses and alloying fusible elements, it additionally contains calcium fluoride and aluminum fluoride in the following the ratio of components, wt.% Sodium fluoride 25-35 Boric anhydride15-25 Calcium fluoride 10-20 Aluminum fluoride Else Sources of information taken into account during the examination 1 .. USSR author's certificate 510,843, cl. C 22 I and 00, 1974.