JPH01160831A - Continuous type hydrator for uo3 and method therefor - Google Patents

Abstract

PURPOSE:To continuously hydrate and chemically activate uranium trioxide having low reactivity, by feeding powder from an inlet where agitating blades are operating and water from a water feeder and taking out the treated powder in a specific state. CONSTITUTION:A raw material powder to be treated is passed from a hopper 29 through a rotary valve 31 and one line and introduced from an inlet 3 positioned just the intermediate point of both shafts into a vessel 100, together with pure water fed from a pure water tank 33 through a constant rate feeder 36, such as constant rate pump, and a line 35 and introduced from the inlet 3 on the upper wall thereinto, is agitated with agitating blades 19 fixed to shafts 15 driven by a power source 43 which is a combination of, e.g., a motor, a speed changer or speed reducer and a coupling and led to an outlet 99 while being hydrated. Cooling water 39 or warm water 41 as a heating medium is suitably made to flow in a jacket 25 to keep the temperature of the substance to be treated within a proper range. A gas discharge port 45 is provided near the outlet and waste gas emerged therefrom is released from a line.

Description

[Detailed description of the invention] [Industrial field of application] The present invention is based on the use of reprocessed recovered uranium (slightly enriched U03) [JF
When producing g, it is used in the hydration process to improve the reactivity of the raw material UO3.

[Prior Art and Problems to be Solved by the Invention] The following are known prior art devices and methods used for this type of application.

■ Stirred hydration method In a batch method, put [103 powder] into a hydration tank and drop water from the top while stirring to form a hydrate.

■ After heating the UO3 powder to approximately 300℃ in a heating and quenching type heating dryer,
Hydrates are formed by cooling the heated UO3 powder in water in a cooling hydration tank.

(2) A spray nozzle sprays a two-phase mixed flow of water and air onto the UO3 powder, which has been fluidized with air in a spray fluidized hydration drying tower (fluidized bed type), to form a hydrate.

These prior art techniques still have technical problems that require improvement as described below.

That is, Continuation is difficult for (2).

Regarding (2), a hydrate with a larger specific surface area can be obtained compared to other methods, but the HF fluorination reactivity is somewhat low.

Regarding (2), it is difficult to obtain a normal fluid state and hydrate due to agglomeration of UO3 powder.

These are some of the difficulties.

The present invention aims to solve the problems of the above-mentioned conventional techniques.

[Means and effects for solving the problems] An object of the present invention is to provide a new means that can eliminate or avoid the above problems.

In the present invention, hydration treatment is carried out continuously by quantitatively supplying uranium trioxide and pure water to a two-shaft continuous hydration machine.

That is, the present invention is an apparatus for continuously hydrating and chemically activating uranium dioxide powder, which has low reactivity. It has a rotating shaft with a rotational axis; has stirring blades arranged side by side on two axes; the range covered by the rotation of the stirring blades on both shafts partially overlaps each other when viewed from the axial direction; However, each stirring blade has a stirring blade arrangement that does not come into contact with adjacent shafts and stirring blades on that shaft; a bottom, side walls, and top wall parallel to the rotation axis, and ends located at both ends thereof. a container comprising a wall and having an inlet for a material to be treated at one end and an outlet for a material to be treated at the other end; The upper end has a weir lower than the inner surface of the top wall; the inner surface of the bottom has a radius slightly larger than the circle formed by the outermost rotational circumference of each stirring blade, and an arc that is concentric with this circle is arranged perpendicular to the rotation axis. Continuous type 1 with a cross-section by a plane; with one or more water supply devices and one exhaust outlet
10. The present invention relates to a hydration device and a hydration method using this device.

The device of the present invention can be said to be a type of mixer or feeder used for mixing or supplying powder or granular materials, but as it is configured with a water supply device and an exhaust port, it is possible to reduce chemical reactivity due to hydration. The inventors had discovered that desirable results can be obtained by continuously treating uranium trioxide, which improves uranium trioxide, with an appropriate amount of water and mechanical stirring.

FIG. 1 shows a conceptual side view of an example of a device according to the present invention, and FIG. 2 shows a conceptual side view for explaining the present invention in detail. By rotating and operating the stirring blade (paddle) 19, the container 10
The powder to be processed, which is quantitatively supplied from one supply port (not shown) in the 0, is hit by the stirring blade, and is moved back and forth (in the axial direction) without being unnecessarily deposited on the bottom or agglomerated. It is randomly oscillated and agitated along with the water vertically and horizontally (in a direction perpendicular to the axis), and moves from the inlet 3 to the outlet 99 and is discharged while performing a hydration reaction. Since the hydration effect is significantly inferior with only one rotating shaft, two
It is considered a book.

The water supply device quantitatively supplies the amount of water necessary for hydrating the object to be treated or a slight excess amount of water from one location on the upper wall.

Water vapor that may be generated as the material to be treated and water are stirred and mixed is led out of the apparatus through the exhaust port.

The desired hydration reaction (U03→003·2H20) is an exothermic reaction, and it is preferable to react at a temperature of 30 to 55° C. for 1 to 5 hours. In order to carry out the reaction at such a suitable processing temperature for a suitable time, the apparatus of the present invention covers at least a portion of its bottom, side walls, and end walls, especially the bottom and side walls, and is equipped with a heating or cooling device. Preferably, it has a jacket through which the heat transfer fluid passes.

Figure 2 is a conceptual explanatory diagram of an example of the device in the present invention.
is a plan view, b is a side view, and C is a cross-sectional view. In this example, the powder to be treated is continuously and quantitatively introduced from the raw material supply duct 1 into the vicinity of the entrance side end of the container 100, which is composed of both end walls 5, both side walls 7, an upper wall 11 serving as a lid, and a bottom 65. The body is equipped with water that is continuously and quantitatively sprayed from a water supply device (not shown) provided on the lid, as well as stirring blades 19 that accompany the rotation of the rotating shaft 15.
The water is stirred by the rotation of the pump and gradually moves toward the outlet 99 while undergoing a hydration reaction, crosses the weir 97, and is discharged from the outlet 99. 1 stirring blade 19 is fixed to the shaft 15 by an arm 17. Although only one stirring blade is shown in Figure 0 for the sake of simplicity, a plurality of stirring blades are usually arranged spirally at the same pitch along each axis, and usually have the same shape. The outermost circles 21 drawn by the rotation of stirring blades attached to adjacent shafts overlap each other as shown in Figure 0, so the stirring blades on adjacent shafts are arranged so that their positions do not normally coincide in the axial direction. be done. Even if they match, it is possible to prevent them from coming into contact by synchronizing the rotations of adjacent shafts and adjusting the phases of stirring blades on adjacent shafts.

A jacket 25 is provided to cover the entire surface of the bottom 65, almost the entire surface of both side walls 7 and the end wall on the entrance side. FIG. 3 is a schematic diagram of an example of a system using the device according to the present invention. The raw powder to be processed enters the container 100 from the hopper 29 via the rotary valve 31 through one line and from the inlet 3 located exactly between the two shafts, and is transferred from the pure water tank 33 to a metering supply device 36 such as a metering pump. The shaft 15 is driven by a power source 43, for example a combination of a motor, a transmission or reducer, and a coupling, along with pure water supplied into the container from the inlet 3 in the upper wall via a line 35. It is stirred by the fixed stirring blade 19 and reaches the outlet 99 while being hydrated. Cooling water 39 or hot water 41 is appropriately flowed as a heating medium through the schematically shown jacket 25 to maintain the temperature of the object to be treated within an appropriate range. An exhaust port 45 is provided near the outlet, and the exhaust gas exiting from the port is discharged through a line 47.

Table 1 shows the general design specifications of the apparatus of the present invention suitable for processing uranium trioxide.

When slightly concentrated uranium trioxide was treated in the reactor shown in Table 1, the results shown in Table 2 were obtained, and highly reactive uranium trioxide hydrate could be continuously obtained in the subsequent process.

Table 1 Design specification capacity (β) 10 Processing capacity (kg/hr) 3 Power (kw) 0.75 Rotating shaft rotation speed (rpm, variable) 0 to 100・Agitating blade shape (flat plate) Fan-shaped outer radius (mm) 37.5 Center angle (degrees) 68 Outermost radius of rotation (mm) 65 Number/axis
12 pitch (mm) 60 pitch angle (
degree) 90 Clearance to the corrugated bottom (mm) Table 2 Test Results [Effects of the Invention] As is clear from the above, the following effects can be obtained by the present invention.

(1) The powder to be treated can be continuously hydrated.

(2) High reactivity during fluorination treatment of the target product.

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams of an embodiment of the device according to the present invention, and Figure 3 is an illustration of a system using the device according to the present invention.
It is an explanatory diagram of an example. 1... Raw material supply duct 3... Population 5... End Wall 7... Side Wall 11... Soil Wall 15... Rotating shaft 17... Arm 19... Stirring blade 21. ... Outermost circle 25 ... Jacket 29 ... Hopper 31 ... Rotary valve 33 ... Pure water tank 35 ... Line 36 ... Constant supply device 39 ... Cooling water 41 ... Hot water 43 ... Power source 45 ... Exhaust port 47 ... Line 65 ... Bottom 97 ... Weir 99 ... Outlet 100 ... Container

Claims (1)

[Claims] 1. An apparatus for continuously hydrating and chemically activating uranium trioxide powder with low reactivity: on two substantially identical horizontal planes parallel to the direction of movement of the object to be treated; It has a rotating shaft with a central axis at Each stirring blade has an adjacent shaft and a stirring blade arrangement that does not contact the stirring blades on that shaft; a bottom, a side wall, and a top wall parallel to the rotation axis, and a a vessel having an inlet for a workpiece at one end and an outlet for a workpiece at the other end; the vessel having an inlet for a workpiece at one end and an outlet for a workpiece at the other end; The top end has a weir lower than the inner surface of the top wall; the inner surface of the bottom is connected to a rotation axis with a radius slightly larger than the circle formed by the outermost rotating circumference of each stirring blade and an arc concentric with this circle. Continuous type U with a cross section in a vertical plane; with one or more water supply devices and one exhaust outlet
O_3 hydration device. 2. The device according to claim 1, further comprising a jacket covering at least a portion of the bottom, side walls, and end walls for passing a heat transfer fluid for heating or cooling. 3. Quantitatively supply the powder to be treated from the inlet of the device below, in which both rotating shafts rotate and the stirring blades operate, and water from the water supply device, and then feed the powder that has passed over the weir to the outlet. A method of taking out the powder to be processed from the outlet and chemically activating the powder to be processed by hydration: Rotation with central axes on two substantially same horizontal planes parallel to the direction of movement of the material to be processed It has a shaft; it has stirring blades arranged in parallel on two axes; the range covered by the rotation of the stirring blades on both shafts partially overlaps each other when viewed from the axial direction; Each stirring blade has an adjacent shaft and a stirring blade arrangement that does not come into contact with the stirring blades on the shaft; it consists of a bottom, side walls, and top wall parallel to the rotation axis, and end walls located at both ends thereof. , has a container having an inlet for the material to be processed at one end and an outlet for the material to be processed at the other end; the container has an inner portion near the outlet end that is further away from the end wall on the outlet end side than the outlet, and the upper end thereof is connected to the upper wall. has a weir lower than the inner surface of the bottom; the inner surface of the bottom has a cross section taken by a plane perpendicular to the axis of rotation, which has a radius slightly larger than the circle formed by the outermost rotational periphery of each stirring blade, and is lined with arcs concentric with this circle. Continuous type U with one or more water supply devices and one exhaust outlet
O_3 hydration device. 4. The method according to claim 3, wherein the object to be treated is treated at a temperature of 30 to 55° C. for 1 to 5 hours.