JPS6411128B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for measuring moisture contained in an object to be measured consisting of a large amount of powder or a mixture of powder and lumps.

[Prior Art] Generally, this type of moisture measuring method is performed as part of the acceptance inspection of copper ore, for example, when a copper smelter purchases a large amount of copper ore.

In this acceptance inspection, the moisture content of a sample taken from the copper ore is measured, and the dry weight of the entire copper ore is calculated from the determined moisture content. Then, the copper content of the entire copper ore is determined from this dry weight and the copper grade of the copper ore. Therefore, in this case, it is of course important to accurately analyze the copper grade, but it is particularly important to accurately measure the moisture content.

Therefore, in this kind of acceptance inspection,
The moisture content of copper ore is measured as follows.
That is, from a large amount of copper ore (for example, 250 tons per lot), a predetermined amount (for example, 25 tons) of sublots is stored in a sublot container by a belt conveyor.
Next, a number (for example, 2) of increments corresponding to that amount are collected from this sublot and stored in an increment container. These steps are repeated until the total number of sublots reaches one lot (10 times in this case). Thereafter, all the increments in the increment container are reduced to obtain a primary sample, and the wet weight of this primary sample is measured. next,
Dry the primary sample and measure its dry weight. Then, the moisture content is determined from these wet weight and dry weight. In addition, the primary sample is further reduced and used as a secondary sample for analyzing copper quality.

[Problem to be solved by the invention] However, in the above moisture measurement method, the number of increments is large (20 in the above case).
Perhaps for this reason, the collected increments are temporarily stored in an increment container. For this reason, there is a risk that the moisture content will evaporate from the increments in the container until the collection of all increments is completed, and the determined moisture content will be smaller than the true value. In particular, in the above moisture measuring method, since the wet weight is measured after the reduction step, water evaporates even during the reduction step, and the determined moisture content tends to become even smaller.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a moisture measuring method that can accurately determine moisture content.

[Means for Solving the Problem] The feature of the present invention is that first, the measuring device is zero-adjusted with an empty drying container placed on the measuring device, and on the other hand, the tip opening is plugged from the inside with a stopper. Push the cylindrical body into the object to be measured, and when the tip of the cylindrical body passes through the surface layer of the object to be measured, move the stopper body to the proximal side within the cylindrical body, and then press the stopper further with the tip opening open. Push the cylinder into the object to be measured, then pull it out from the object, then move the stopper again to the tip side to dispense the increment directly from the cylinder into the dry container and measure its wet weight. Furthermore, by repeating the operation several times in sequence, zeroing the weighing device with the increment still in the drying container, then inserting the next increment from the cylinder into the drying container and measuring its wet weight. Find the total wet weight of the increment,
The increment is then dried, its total dry weight is measured, and the moisture content is determined from the total wet weight and total dry weight.

[Example] Hereinafter, an example of the present invention will be described with reference to flow sheets shown in FIGS. 1 to 3. In this embodiment, a large amount of copper ore that has been shipped is loaded onto trucks and delivered to the recipient side, and moisture content is measured as part of the acceptance inspection at the time of delivery.

Therefore, in this embodiment, the loaded copper ore is sequentially transferred to a large number of trucks, the copper ore loaded on each truck is weighed in that state, and the weighed values for all trucks are integrated. We first check the weight of all the copper ore that has been shipped.

After the truck loaded with copper ore arrives at the recipient, moisture content is measured according to the flow sheet shown in FIG.

First, as shown in FIG. 1, a predetermined number of increments are sampled from copper ore loaded on a truck using a sampling device. In this case, water often evaporates from the surface layer of the copper ore during transportation by truck, leaving that portion dry.
Therefore, increments are extracted only from inside the copper ore. Note that a sample collection device used in such a collection method will be described later.

Next, the weight, ie, wet weight, of the sampled increment is immediately measured after each increment is sampled. This incremental sampling and wet weight measurement is repeated until the copper ore brought in by truck reaches a predetermined sublot amount. An example of such a method for measuring wet weight is shown in FIG.

In other words, in this case, the weighing device is a balance connected to a computer, and this device requires lot number input to the computer,
Zero adjustment of the balance, measurement of the weight of the drying container for storing the increments, and subsequent zero adjustment of the balance are performed in advance and kept on standby. Then, the increments collected by a sample collection device, which will be described later, are placed directly into a drying container and their wet weight is measured, input into a computer, and printed.

Next, the balance is zeroed while the increment whose wet weight measurement has been completed remains in the drying container.
The next increment is then placed in the dry container and its wet weight is measured. This wet weight measurement is
This is repeated in sequence until the number of increments corresponds to the number of increments corresponding to the sublot, and the total wet weight in the sublot is determined.

Thereafter, another dry container is placed on the balance and the wet weight of the increment is measured again. In this way, repeat until the total sublot amount reaches the lot amount to complete the incremental wet weight measurement.

Next, the increment stored in the drying container is
Dry in each drying container.

Thereafter, the total dry weight of the increments stored in all the drying containers is measured, and the moisture content is determined from the total wet weight determined previously.

Regarding these dry weight measurements and moisture content calculations,
In this embodiment, a weighing device in which a computer is connected to the above-mentioned balance is used, and the measurement is carried out according to the flow sheet shown in FIG. That is, inputting the lot number into the computer and zeroing the balance are performed in advance. The dry container containing the increments is placed on the balance of the weighing device thus set, and the total dry weight of the increments of the sublot amount is measured. The measured values are input into the computer and printed out. Thereafter, the dry weights of the increments in other drying containers are sequentially determined. Once the dry weight measurements of all the increments have been completed, the computer is instructed to calculate the moisture content and the results are printed.

Incidentally, the increments for which the total wet weight measurement and total dry weight measurement have been completed as described above are mixed as a whole, and then pulverized and reduced so that the maximum particle size is 1 mm or less. The reduced sample is further finely ground to pass through a 100 mesh sieve. It is then further reduced and packed into bags as samples for copper quality analysis.

Here, in the method of this invention, the collected increments are not stored in a container or reduced, but are immediately placed in a drying container and their wet weights are sequentially measured. Water does not evaporate from the increment until it is measured, so the moisture content of the copper ore can be accurately determined. Moreover, since the wet weight is measured for each increment, even if the increment in the drying container that has already been measured dries and its weight changes, it will not affect the measurement of the total wet weight in any way. , it becomes possible to measure the moisture content more accurately. In addition, the wet weights of multiple increments are added to determine the total wet weight, these multiple increments are dried simultaneously to measure the total dry weight, and the moisture content is determined from these total wet weights and total dry weights. Therefore, the measurement accuracy is also excellent. At this time, since all measurements can be performed using only one drying container, handling is simple and rational.

In addition, as a result of determining the moisture content of the same copper ore using the conventional moisture measurement method and the moisture measurement method of the present invention, the moisture content was 7.792% with the conventional method, and 7.904% with the method of the present invention. It was hot. The difference of 0.112% is estimated to be the amount of water evaporated from the start to the completion of incremental sampling in the conventional method and during the reduction step. It goes without saying that the copper quality of the sample obtained by the conventional method and the sample obtained by the method of the present invention was the same.

Next, an example of a sample collecting device used for collecting increments when carrying out the method of the present invention will be described with reference to FIGS. 4 to 14.

Reference numeral 1 in the figure is a frame. This frame 1
is installed, for example, on the second floor of a building built on the side of a passageway for trucks loaded with metal concentrate, and runs from the building side to the passageway side at a predetermined angle, for example 60°, with the horizontal line. It is provided with two mutually parallel support beams 1a extending diagonally downward. A rail 2 extending in the longitudinal direction of the support beam 1a is laid on the support beam 1a. This rail 2
As shown in FIG.
It is installed so that it can be moved through. Mobile trolley 3
is driven by a lifting cylinder 5 installed at the upper end of the frame 1. Note that a stopper 6 is fixed to the lower end of the support beam 1a, and this allows the movable trolley 3 to move to the rail 2.
It is designed to prevent it from falling downward. Further, support tubes 8 are provided on both left and right sides in FIG. 6 of the upper surface of the movable trolley 3 via shafts 7 so as to be rotatable in the front and back directions in the figure. Reinforcing members 9 and 10 are spanned between the support tubes 8 and 8 above and below the shaft 7, respectively. On the upper reinforcing member 9, a tilting cylinder 11 is attached to a moving carriage 3 along its axis.
It is rotatably attached to the top surface of the As shown in FIG. 7, the tip of the rod 11a of the tilting cylinder 11 passes through a recess 3b formed at the upper end of the top plate 3a of the movable cart 3, and is brought into contact with the bottom plate 3c. Also Rod 11a
A stopper ring 12 having a spherical upper surface is fixed in the middle with a bolt 13 with a slight gap between the upper surface and the lower surface of the top plate 3a of the movable cart 3. Therefore, the tilting cylinder 11
As the rod 11a extends and retracts, the support tube 8 rotates relative to the movable cart 3.

Further, a cylinder 14 is fixed to the lower end of the support cylinder 8 with its axis aligned with the axis of the support cylinder 8. This cylindrical body 14 is used to take out the metal concentrate M that has entered into the metal concentrate M as a sample when it is pushed into the metal concentrate M. The head 14b is screwed onto a certain lower end. The lower end of the head 14b is open to take the metal concentrate M into the cylinder 14. Moreover, the opening 1
4c is formed to have a smaller diameter than other parts of the cylinder body 14 in order to prevent the metal concentrate M that has entered the cylinder body 14 from spilling out.

On the other hand, a sample dispensing cylinder 15 is fixed to the upper end of the support tube 8 with its axis aligned with the axis of the support tube 8 . The rod 15a of the cylinder 15 extends into the cylindrical body 14 through the support tube 8, and a stopper 16 is screwed and fixed to the tip thereof. The stopper 16 is moved or positioned within the cylindrical body 14 as follows by the extension and retraction of the rod 15a of the cylinder 15. That is, until the tip of the cylindrical body 14 passes through the surface layer of the metal concentrate M where the water content has decreased, the tip of the cylindrical body 14 is fitted into the opening 14c of the cylindrical body 14 and plugged as shown in FIG. In addition, when the tip of the cylinder 14 passes through the surface layer of the metal concentrate M and is further pushed in, the opening 14 is located at the upper end, which is the base end side, of the cylinder 14.
c is opened to allow the metal concentrate M to enter the cylinder 14, and when discharging the metal concentrate M that has entered the cylinder 14, the metal concentrate M is moved from the upper end of the cylinder 14 to the lower end. It moves to push out the metal concentrate M from inside the cylindrical body 14 to the outside. In addition, plug body 1
When 6 is fitted into the opening 14c, the end protruding from the opening 14c has a tapered shape that becomes smaller in diameter as it goes toward the lower end. The resistance when pushing into the concentrate M is reduced.

Next, a case in which a sample is taken from metal concentrate loaded on a truck using the sample collecting apparatus constructed as described above will be described with reference to FIGS. 9 to 14.

FIG. 9 shows a state in which the sample collection device is on standby. In this standby state, the cylinder body 14 is positioned at the upper end side of the frame 1, and the stopper body 16
is fitted into the opening 14c of the cylindrical body 14.

When the truck T loaded with metal concentrate M arrives at a predetermined position, the cylinder 5 is activated and the cylinder 14
The cylindrical body 14 is moved downward until the opening 14c passes through the surface layer portion of the metal concentrate M where the moisture content has decreased.
Immediately after the opening 14c passes through the front and back portions, the cylinder 5 is stopped (see FIG. 10).

Next, the dispensing cylinder 15 is operated to position the stopper 16 at the upper end of the cylinder 14. Thereafter, the cylindrical body 14 is further pushed into the metal concentrate M to a predetermined depth, and the metal concentrate M is introduced into the cylindrical body 14 (see FIG. 11).

Next, the cylinder 14 is raised to the standby position by the cylinder 5 (see FIG. 12).

Next, the tilting cylinder 11 is operated, and the cylindrical body 1
The opening 14c of No. 4 is directed vertically downward. Note that a drying container C for receiving the above-mentioned sample is arranged below the opening 14c. Then, the stopper 16 is moved downward by the dispensing cylinder 15, and the collected sample is directly dispensed into the drying container C (see FIG. 13), and its wet weight is measured.
Thereafter, the cylinder 14 is reversed by the tilting cylinder 11 (see FIG. 14), and the entire apparatus is returned to its original standby state.

According to the above sample collection method, the surface layer of the metal concentrate M, whose moisture content changes due to considerable dryness during transportation, is not mixed in, and the metal concentrate M, whose moisture content does not easily change, can be collected. Since the increments are collected only from the deep part, it is possible to obtain a sample that accurately represents the moisture content of the entire metal concentrate M.

The above operations may be performed manually, but if controlled by a timer, limit switch, etc., the steps from increment collection to wet weight measurement can be performed automatically.

Furthermore, in the above, the case where the method of the present invention is applied to the moisture measurement of copper ore has been explained.
The method of the present invention may be applied to powders other than copper ore, or mixtures of powder and lumps, such as iron ore and the like.

[Effects of the Invention] As explained above, according to the moisture measuring method of the present invention, first, a plurality of increments are sampled only from inside the object to be measured in the cylinder, and the increments inside the cylinder are directly measured on the measuring device. Dispense the increment into the drying container and measure its wet weight, then zero-adjust the weighing device with this increment still in the drying container, and then put the next increment from the cylinder into the drying container and measure its wet weight. The measuring operation is repeated until all of the above-mentioned increments are completed to obtain the total wet weight of these increments, and then the increments in the drying container are dried and their total dry weight is measured. The moisture content is determined from the weight and total dry weight.

Therefore, according to this moisture measurement method, the moisture content of the measured object can be accurately represented without contaminating the surface layer of the measured object whose moisture content has changed due to drying during transportation. Increments can only be collected from the deep part, and the wet weight of each increment is measured immediately after collection, so even if the increment in the drying container that has already been measured dries and its weight changes, the total moisture will not be calculated. Since it does not affect the weight measurement in any way, it is possible to measure the moisture content of the object with great accuracy, and it is also possible to measure the moisture content from the total wet weight and total dry weight of multiple increments. As a result, measurement accuracy can be improved.In addition, since a series of measurements are carried out using only one drying container, advantages such as ease of operation and excellent measurement rationality can be obtained.

[Brief explanation of the drawing]

Figures 1 to 3 are flow sheets of an embodiment of the method of the present invention, and Figures 4 to 14 are diagrams showing flow sheets of an embodiment of the method of the present invention.
The figures show an example of a sample collecting device used for incremental sampling, and Fig. 4 is a side view thereof, Fig. 5 is a partially omitted enlarged view taken along the - line in Fig. 4, and Fig. 6 is a view similar to Fig. 4. 7 is a partially omitted enlarged view taken along the - line in Fig. 4, Fig. 8 is an enlarged view of the circular part in Fig. 6, and Figs. 9 to 14 are views of the device. FIG. 1...Frame, 3...Moving trolley, 14...Cylinder body, 16...Bung body, M...Metal concentrate.

Claims (1)

[Scope of Claims] 1. A method for measuring the moisture content of a measured object by taking a plurality of increments from a measured object consisting of a large amount of powder or a mixture of powder and lumps, First, the measuring device is zero-adjusted with an empty dry container placed on the measuring device, and in parallel with the zero-adjustment of the measuring device, a cylindrical body whose tip opening is closed from the inside with a stopper is covered. When the tip of the cylindrical body passes through the surface layer of the object to be measured, the stopper is moved to the proximal side within the cylindrical body, and the cylindrical body is further inserted with the tip opening opened. The cylinder is pushed into the object to be measured, and then the cylinder is pulled out from the object to be measured.Then, the stopper is moved to the tip side again to dispense the increment from the cylinder directly into the drying container, and immediately lose its wet weight. At the same time as measuring, the measuring device is zero-adjusted while the increment remains in the drying container, and then the next increment is put into the drying container from the cylinder and its wet weight is measured. , determine the total wet weight of the increment by sequentially repeating the process until all of the increments are completed, then dry the increment and measure its total dry weight, and calculate the total wet weight from the total wet weight and the total dry weight. A moisture measuring method characterized by determining the moisture content.