The processing of copper sulfide ores is done by flotation. The ground copper sulfide ores are enriched with water and a foaming agent to skim off quartz or silicates. The resulting copper concentrate has a copper content of 20-40%.
During pyrometallurgical extraction, SO2 is produced, which is technically oxidized with atmospheric oxygen to sulfur trioxide (SO3) (contact process). A copper content of about 96 – 99% remains. For a purity level of 99.99%, electrolytic refining follows. This is necessary because the thermal and electrical conductivity of copper is greatly affected by impurities.
Difficulty in density and concentration measurement of sulfuric acid
In the process of sulfuric acid production, process engineers often face a challenge:
Numerous measurement methods intended to measure the concentration or density of sulfuric acid function inadequately at a concentration of 85m% - 99m%. Problems arise particularly when the underlying physical value of the concentration or density measuring device does not change with a change in concentration.
For example, the diagram clearly shows that conductivity sensors provide poor measurement results in a concentration range of sulfuric acid from 80m% - 97m% because the conductivity of the liquid hardly changes in this concentration range. For this reason, conductivity sensors exhibit extremely low measurement accuracy when sulfuric acid is to be analyzed in this measurement range.
The same applies to density measuring devices, where the density of the liquid itself is to be evaluated. It turns out that especially in measurement ranges above 90m%, the density of the liquid hardly changes. Therefore, many simple density measuring devices have major problems when they are to be used to measure the concentration of sulfuric acid in this measurement range.
LiquiSonic® sound velocity measurement in comparison
Precisely measure the concentration and density of sulfuric acid using sound velocity
Unlike conductivity sensors or density sensors, ultrasonic measuring devices are capable of measuring the concentration of sulfuric acid with extreme precision. With a change in the concentration of sulfuric acid, the sound velocity also changes significantly. Therefore, concentration measuring devices whose sensors evaluate sound velocity provide much more accurate measurement results than conductivity measuring devices or density measuring devices.
Application
In pyrometallurgical extraction, the copper concentrate is slagged with the addition of SiO2 in a flame furnace at 1200 to 1400 °C. This produces a melt of copper and iron sulfide, which is separated from the slag phase as so-called copper matte. The liquid copper matte is poured into a converter and the iron sulfide is oxidized to sulfur dioxide SO with the supply of air.2 Oxidized. Resulting SO2 is converted to sulfur trioxide (SO3) is oxidized (contact process) and the SO3 is introduced into 96% sulfuric acid in the absorber, where highly concentrated H is produced by adding water2SO4 or oleum is formed. In blending, the H is then diluted to the targeted concentration2SO4 is diluted to the targeted concentration.
The individual process steps can be continuously monitored inline and optimally adjusted using Liqui-Sonic® measurement technology. Due to the high dependence on sound velocity, an accuracy of +/- 0.05 m% is achieved with sulfuric acid.
The LiquiSonic® immersion sensors can be easily installed in the pipelines after absorption or sulfuric acid production or blending. The LiquiSonic® Controller 30 can be connected to up to 4 sensors. This allows multiple measurement points to be monitored simultaneously.
Typical measurement ranges:
Concentration range H2SO4: 80 - 100 m%
Temperature range: 20 - 90 °C
Concentration range oleum: 0 - 30 m%
Temperature range: 10 - 60 °C
Customer benefits
LiquiSonic® ensures precise analysis and monitoring of H2SO4 or oleum concentration with permanent data recording. The robust sensor design and the choice of special materials, such as Hastelloy C2000, ensure long system process runtimes.
LiquiSonic® reduces time-consuming laboratory measurements:
- Time saving: 1 h per day
Compared to conductivity and density measurement, it generates LiquiSonic® a clear signal in the concentration range of 80 to 100 m% and thus provides reliable process information at any time.
Copper is extracted by mining copper sulfide ores, which contain about 2% copper. Raw metal extraction involves various process steps.
