JPS599607B2 - Distilled zinc production method and equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for producing distilled zinc of low lead grade used as a raw material for galvanized iron plates and the like.

Zinc is in great demand for the production of galvanized iron sheets, and the zinc used as a raw material for its production is generally called mixed zinc, which contains 0.01 to 0.3% lead and 0.20 to 0.0% aluminum.
．． It is a low grade zinc containing 40% lead.

Conventionally, in order to obtain such compounded zinc, for example, when explaining the electrothermal distillation method, zinc 98, which is produced in an electric furnace, is
．． It is sent to a rectifying lead tower containing zinc having a composition of about 1.1% lead, removing Pb (lead), and Fe (iron), and then removing cadmium components in a rectifying cadmium tower.
A measured amount of lead is added to this purest zinc and dissolved to obtain a zinc compound containing 0.01 to 0.3% of Pb.

As mentioned above, this manufacturing procedure requires three steps: deleading, removing cadmium, and measuring and adding lead.

In such a device, for example, 1.3 77? ZX O. 7
For every six rectified lead towers with a rectangular cross section of 6 m and a height of about 1277 mm, one rectified cadmium tower of the same size must be installed.

In other words, in order to obtain mixed zinc, a large number of rectification columns and their control must be installed in addition to the above three steps, which requires considerable equipment costs, maintenance costs, equipment and operators for controlled operation. The problem is that it requires

First, the relationship between a conventionally used electric furnace and a capacitor will be explained with reference to FIG.

Sintered ore and sized coke are fed into the furnace by an ore feeder 2' located at the top of the electric furnace 1'.

An upper electrode 3a/ and a lower electrode 3b' are attached to the electric furnace 1', and heating is performed using the charge as a conductor.

The generated zinc vapor is sent to the paper ring section 4 together with CO gas.
' (zinc vapor outlet) via a connecting box 5' to a condenser 6'.

After the zinc component has been separated, the sintered ore residue and coke ash are taken out of the electric furnace by an ore discharger 7'.

Therefore, in such a process, zinc is obtained with a composition determined by the ratio of components evaporated and separated from the sintered ore, and there is no compositional control at this stage.
It is something.

Therefore, zinc having a composition of about 98.5% zinc and 1.1% lead is usually obtained, which requires further purification.

This invention connects to the zinc vapor outlet of the furnace to
A condenser is installed to remove the lead component contained in the zinc vapor to adjust the component, and then this zinc vapor is sent to a second condenser to be condensed.The cadmium component is removed by a rectifying cadmium column, which is not possible in many conventional systems. The purpose of the present invention is to propose a method and an apparatus for the method that eliminates the need for a necessary rectifying lead tower and that can obtain mixed zinc with the intended components.

In short, this invention is a method for producing distilled zinc by condensing zinc vapor using a plurality of condensers that communicate with each other, and the temperature of the zinc vapor flowing in the first condenser connected to the zinc vapor outlet of the furnace is controlled at 800°C to 1000°C. A second capacitor is installed downstream of this first capacitor, and the second capacitor is free of lead.
．． A method for producing distilled zinc that produces distilled zinc with a low lead grade of 3% or less.

Further, the present invention provides a first condenser connected to an outlet of a furnace for sending out zinc vapor, and having a baffle for separating droplets of molten metal such as lead iron that become impurities in zinc when condensed; The distilled zinc production apparatus is characterized in that it includes a second condenser located downstream of the first condenser to condense zinc vapor, and produces distilled zinc with a low lead grade of 0.3% or less.

First, let's talk about the melting points and boiling points of the ingredients that are problematic in the production of compounded zinc.Lead has a melting point of 327.4℃ and a boiling point of 1740℃.
℃, iron has a melting point of 1539℃ and a boiling point of 2740℃.

On the other hand, zinc has a melting point of 419.46°C, which is higher than lead, but a boiling point of 906°C, which is lower than that of lead.

The inside of the second capacitor 6, which holds zinc in a molten state, is always maintained at about 480°C.

A detailed explanation of this method in the electrothermal distillation method will be given below. S. P. It can also be applied to dry zinc ball manufacturing methods such as the retort method and the retort method.

Therefore, as shown in FIG. 1, if a capacitor 6/IJ'' having a structure similar to the second capacitor of the present invention is directly connected to the paper ring part of the electric furnace, the zinc vapor discharged from the electric furnace Zinc 98.5 with the same composition as
Molten zinc containing lead iron cadmium, etc. with a lead content of about 1.1% is obtained.

In this invention, the boiling point of Pb and Fe is over 1000°C, while the boiling point of zinc is 906°C.
Focusing on the following, the temperature of the zinc vapor sent out from the electric furnace is set to 1000°C or lower and 800°C or higher, preferably 800°C or higher.
Pb is maintained at 50°C or higher and 910°C or lower by a baffle installed in the flow path of the high-temperature first capacitor connected to the electric furnace.
, FeO droplets are separated to obtain molten zinc having a desired zinc component in a second condenser.

It is generally considered desirable to operate the electric furnace so that the temperature of the gas containing zinc vapor sent out from the electric furnace is 950° C. from the viewpoint of productivity of the furnace.

If the temperature is lower than this, the productivity of the furnace will deteriorate and this is not desirable.

Next, the structure of an apparatus according to an embodiment of the present invention will be explained with reference to FIG.

Zinc vapor at the outlet of the paper ring section 4 of the electric furnace 1 is preferably at a temperature of 950°C, but generally has a high temperature of 1000 to 1250°C and contains CO gas.

In the present invention, a high-temperature condenser (in the drawing, a duct-shaped condenser 8 is connected as an example) is connected to the paper ring portion 4, and a plurality of zinc vapor flow paths are connected to the high-temperature first condenser 8. A baffle is provided to form a curved zinc vapor flow.

When the zinc vapor flowing out from the paper ring section 4 flows through the high temperature first condenser 8, the boiling point of PB is 1740.
Since the iron temperature is 2740°C, it contains fine droplets of Pb and FeO, which come into contact with the baffle 9 due to the bending flow and are separated from the zinc vapor.

When such droplets collect and drip onto the duct floor, they can be taken out from the outlet 10.

In addition, the zinc vapor temperature is 1
Although it is desirable to lower the temperature to below 0.000°C, lowering the temperature too much will cause the problem of too much zinc condensation in the first condenser.

Therefore, the above-mentioned 1000°C to 800°C, preferably 910°C to
It is desirable to have equipment for reducing and maintaining the temperature of the steam zinc to 850°C.

In this invention, an inert gas for temperature control such as N2 is used.
A nozzle 11 for blowing gas is made of ceramic that can withstand high temperatures, and is provided on the paper ring portion 4 side, that is, on the high temperature side.

Or C generated in an electric furnace instead of N2 gas
O gas can also be used.

The CO gas used at this time is preferably one that has been passed through a cooler and drying process and has a low temperature and low moisture content.

Further, the gas temperature at the outlet of the paper ring section 4 is measured by a temperature measuring device 12, and its signal is sent to a control box 13.

Also, a connection duct 16 connects the high temperature first capacitor 8 and the low temperature second capacitor 6 by controlling the valve 14 provided in the N2 gas supply pipe 15 by a command signal from the control box 13 to control the N2 gas supply amount. Ensure that the gas temperature inside is appropriate.

A temperature signal from the gas temperature measuring device 17 in the connecting duct 16 is sent to the control box 13, and the temperature relationship between the inlet and outlet of the first condenser 80, which is at a high temperature, is adjusted to an appropriate value.

A zinc bath is formed in the low-temperature second condenser, and the temperature of the zinc liquid is maintained at about 450 DEG to 480 DEG C. to effectively condense the zinc vapor.

Also number 1. Positioning the capacitor almost horizontally facilitates the installation of a hole 18 on the upper surface of the capacitor for removing baffle deposits and facilitates the work of the operator.

Furthermore, taking measures to prevent the generation of zinc oxide by heating the wall portion of the first capacitor is useful in reducing clogging troubles caused by zinc oxide in the first capacitor.

Furthermore, in order to eliminate or minimize the need for N2 gas for gas cooling, it is effective to lower the gas temperature at the zinc vapor outlet as much as possible.

Example Sintered ore containing zinc oxide was reduced in a reduction furnace, and metal vapor containing impurities generated by the reduction was used to obtain a zinc solution using a first condenser and a second condenser.

6. The temperature of the first capacitor is 900°C and a baffle is provided. OT/day (lead grade 6, iron grade 0.05
%) was obtained.

In the second condenser, a condenser with indirect cooling means is installed so that the recovered zinc solution reaches 500℃.
Distilled zinc with low lead grade (lead grade 0.08%, iron grade 0.008%) was obtained.

By carrying out this invention, it is possible to remove Pb, Fe, etc. with the first condenser that maintains the temperature of zinc vapor within an appropriate range, thereby eliminating the need for a conventional rectifying lead column, and furthermore, it is possible to remove Pb, Fe, etc. It makes it possible to scale lead-grade distilled zinc, and has various effects such as simple and easy operation control.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view of a conventional electric furnace and capacitor;
The figure is a longitudinal cross-sectional view showing a control system along with the relationship between an electric furnace, a high-temperature first capacitor, and a low-temperature second capacitor in a case where a high-temperature first capacitor according to the present invention is provided. 1... Electric furnace, 4... Paper ring part (zinc vapor outlet part), 5... Connecting box, 6... Second
Capacitor, 8... High temperature first capacitor, 9...
Batsuful, 11...N2 gas nozzle, 12...Temperature measuring device, 13...Control box.

Claims (1)

[Claims] 1. In a method for producing distilled zinc by condensing zinc vapor using a plurality of condensers connected to each other, the temperature of zinc vapor flowing in a first condenser connected to a zinc vapor outlet of a furnace is set to 800°C to 1000°C. A second condenser is installed downstream of this first condenser, and the second condenser produces distilled zinc with a low lead grade of 0.3% or less. Characteristic method for producing distilled zinc. 2. A first condenser connected to the outlet of the furnace for sending out zinc vapor and having a baffle for separating molten metal droplets such as lead and iron that become impurities in zinc during condensation, and the first condenser for the flow of zinc vapor. and a second condenser located downstream of the condenser for condensing zinc vapor, and producing distilled zinc with a low lead grade of 0.3% or less.