AU600840B2 - Method for extracting samples from a slurry flow - Google Patents

Description

A

AUSTRALIA

PATENTS ACT 1952'0 0 8 0 Form COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: Complete Specification-Lodged: Accepted: Lapsed: Published: This dn.':ument contains the am;idments made undr ction 49 and is correct for printing.

Priority: Related Art: 0 o o 0 o 9 o( or S0 f 1 0 00 t TO BE COMPLETED BY APPLICANT Name of Applicant: OUTOKUMPU OY Address of Applicant: TOOLONKATU 4 00100 HELSINKI

FINLAND

Actual Inventor: Address for Service: GRIFFITH HACK CO., 601 St. Kilda Road, Melbourne, Victoria 3004, Australia.

Complete Specification for the invention entitled: METHOD FOR EXTRACTING SAMPLES FROM A SLURRY FLOW The following statement is a full description of this invention including the best method of performing it known to me:- 2P" i_ i Y--r 1A- METHOD FOR EXTRACTING SAMPLES FROM A SLURR. FLOW Field of the Invention The present invantion relates to a method for extracting samples each from any one of several slurry flows and for transporting these samples into an analyzer so that each sample, without an additional treatment such as dilution, can be analyzed.

Description of Prior Art From the Soviet Union inventor's certificates 836553 and 1075106 there is known an automatic sampling system for a *process flow. In this system, the sample is first collected into a tank, where the sample is diluted with water into which pressurised air is also fed in order ooo to transport the sample pneumatically into an analyzer oo....unit. The analyzer unit consists of a separation tank for 15 the separation of the air used in the transportation, as o o well as a sample circulation system connected to the separation tank, which circulates the sample through the analyzer. Thus a continuous sample flow through the analyzer is created. Consequently, in the method of the Soviet Union inventor's certificates 836553 and 1075106, o 4° the sample must be treated by diluting it with water.

Thus the sample no longer corresponds to the real, 0 original process flow. The circulation of the sample 1 O o4 through the analyzer by means of a separate system is a troublesome method which brings about additional expenses.

04 The circulation process employs an air jet pump, which o 0: continuously mixes air into the slurry. With 0o concentration plants, there is easily created foam, which binds part of the minerals so that the representative quality of the sample is reduced.

0 P- N*I 2 Summary of the Invention An object of the present invention is to eliminate some of the drawbacks of the prior art and to realize a new and improved method for drawing samples from any one of zeveral slurry flows, as well as to transport the sample for analysis such that the otiginal composition of the slurry flow can advantageously be maintained without diluting the sample.

According to one aspect of the invention there is provided a method for extracting samples from slurry flows and transporting the samples by sampling lines in an undiluted form into an analyzer for analksis, each sample being sampled at a point in individual ones of the slurry flows, the method comprising the steps of: extracting each sample from its slurry flow for a period of at least the duration of the analysing process performed by the analyzer on each sample; o creating a continuous flow of samples through the analyzer by sequencing the extracted samples, whereby 20 use of the analyzer can be optimized; and o 0 0 returning each analyzed sample to its slurry flow.

Preferably, at least one sampler per each slurry flow to be treated is connected to the analyzer unit. The 25 sampling is advantageously carried out so that the sample 0000 flow which has passed through the sampler can be cut off o o so that the main slurry flow does not cause any danger of blocking for the sampling members. This type of sampler S0 has been described for instance in Australian patent application no. 14799/88. It is also possible to draw a sample from the slurry flow in continuous operation as o long as it is necessary from the point of view of the analysis.

The sample obtained from the slurry flow is transported to the analyzer, advantageously by making use of the gravitational force. If necessary, the >.e1_ 3 transportation can be effected by means of a process pump, or the sample is transported pneumatically by means of pressure air.

Preferably, each sampler can be connected to a specific measuring cell, but in a preferred embodiment of the invention, several samplers are connected to one and the same measuring cell. Thus it is possible to provide the analyzer unit, prior to the measuring cell proper, with a sample multiplexer, whereby the desired sample flow can be conducted for analysis. The sample multiplexer can also be used in the removal of air from pneumatically transported sample flows or in the levelling of semi-continuous sample flows. The sample multiplexer may not necessarily be needed, rather a separate inlet connection for each sample flow can be provided in the analyzer, and since the sample flow from the rest of the .o slurry flows can be cut off, only that one desired sample 0 o_ flow is conducted to be analyzed in the analyzer at a 0 time.

20 Preferably, the slurry amount used as the sample D0d0 S0 can advantageously be returned into the slurry flow.

Furthermore, the circulation load caused by the analyzer can be cut down, which in part reduces both the disturbances caused for the process by the analyzer and the pumping expenses. Moreover, the prevention of the 00041 04-, danger of blocking in the sample lines can be improved, because the sample lines between separate samples can be cleaned for instance by rinshing, and because the sample o* flow can be cut-off, by means of the samplers, so that the sample flow is removed even from the most critical points of the sampling line after the cut-off. The sequential use of the sample lines also reduces the wearing of the o sample lines for example in comparison with the prior art arrangements.

Preferably, the sampling and the sample transportation are controlled by means of an advantageously programmable sequence control unit. Thus _,the control unit can be programmed for instance to measure ,the height of the sample surface in the containers prior 4 d 0? r -4to the transportation, or the progress of the sample in the pipes. Furthermore, the operation of the various devices and the valves provided therein is controlled, so that information is obtained as for the advantageous time for cutting off the sample flow, as well as the time when, for example, a sample using pneumatic transport is ready for transportation. This enables the connecting of the sampling and transportation equipment to be compatible with the sample analyzer, so that the employed analyzer can be any known analyzer, either continuously or noncontinuously operated. The use of continuously-operated analyzer is possible because an essentially continuous sample flow, at least for the duration of the sampling operation, is created from the batchwise or discontinuous samples. The employed analyzer can advantageously be for instance an apparatus based on 4o x-ray fluorescence or x-ray diffraction.

Detailed Descriptioi of Preferred Embodiments ous An embodiment of the invention is explained in S 20 more detail below with reference to the appended drawing, which illustrates a process diagram.

According to the drawing, the analyzer 1 is provided with a sample multiplexer 2, which conducts the desired sample flow from any of the sample lines 3, 4, or 6 into the analyzer to be analyzed. The sample from the sample line 3 is extracted by using a suction pipe 7 and by means of an air lift, and is conducted further into ,the sample multiplexer 2 by means of the gravitational force. The suction and discharge sequences follow in rapid succession so that an advantageously semi-continuous sample flow is created in the sample multiplexer. The sample from the slurry flow into the sample line 4 is obtained by employing pressure sampling, in which case the sampling nozzle 10 provided in the pressurized slurry flow i 5 pipe 9 causes the sample flow to deviate from the slurry flow when the valve 11 is open. Thus the sample flow is made to proceed, by means of the pressure prevailing in the pipe 9, into the sample multiplexer 2. The sample into the sample line 5 is extracted from the slurry flow in the same fashion, by employing the nozzle 10, as into the line 4. In order to transport the sample into the sample multiplexer, the pump 12 is used in addition to the process pressure, because the height difference between the location of the sample multiplexer and the sampling point becomes too large if the transportation only makes use of the process pressure. The sample in the sample line 6 is conducted into the sample multiplexer 2 as a pneumatic transportation. Sampling from the non-pressurized slurry flow pipe 13 is advantageously carried out by employing the apparatus of Australian So patent application no. 14799/88 in which case the sample is first conducted into a collecting tank 14, whereafter pressurized air is fed into the desired sample amount so that pneumatic transportation is made possible. Control rof the selection of which sample is to be passed to the analyzer 1 is performed by the sequence control unit connected to the sample multiplexer 2. The sequence control unit 15 can either control the separate sampling members to provide a sample in a determined sequence, such that a continuous flow can be supplied to the analyzer 1 o 0: ofrom several discontinuous flows, else, if the separate sampling members can not be controlled, the sequence o0 control unit 15 can observe whichever is sending a sample and appropriately control the sample multiplexer 2 to provide essentially continuous operation of the analyzer 1. In this way, use of the analyzer 1 can be optimized.

'o Although only one analyzer 1 is illustrated in the drawing, it is possible that the sample lines can also be conducted into separate analyzers. Similarly, the number of sample lines using different methods of Q4[i!: hI' 1,1~u i- 6 transportation could be several, in which case, for instance, those sample flows which use pneumatic transportation could be connected to a particular one of the separate analyzers. Furthermore, when employing separate analyzers, the sample line can also be made to operate continuously, so that collecting a sample is not necessary, which results in the treatment of the sample essentially within real time. In addition to this, the various ways of transportation are not limited to a certain sampling method, but for example a sample extracted by means of a suction pipe can, instead of the transport method based on the gravitational force and illustrated in the drawings, be transported pneumatically.

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Claims (9)

1. A method for extracting samples from slurry flows and transporting the samples by sampling lines in an undiluted form into an analyzer for analysis, each sample being sampled at a point in individual ones of the slurry flows, the method comprising the steps of: extracting each sample from its slurry flow for a period of at least the duration of the analysing process performed by the analyzer on each sample; creating a continuous flow of samples through the analyzer by sequencing the extracted samples, whereby use of the analyzer can be optimized; and returning each analyzed sample to its slurry flow.

2. A method as claimed in claim 1, wherein the sequencing of the extracted samples is performed by a sequence control unit.

3. A method as claimed in either of claims 1 or 2, wherein each sample is extracted from a slurry flow by means of suction.

4. A method as claimed in either of claims 1 or 2, wherein, for a pressurized slurry flow, a sample therefrom is extracted by a nozzle extending into the slurry flow.

5. A method as claimed in any one of the preceeding claims, wherein any number of the samples are transported in their sampling respective lines under the force of gravity.

6. A method as claimed in any one of claims 1-4, wherein any number of the samples are transported in their o o respective sampling line using pneumatic forces. o°

7. A method as claimed in any one of claims 1-4, wherein any number of the samples are transported in their respective sampling line driven by the pressure of the slurry flow. I 8

8. A method as claimed in any one of claims 1-4, wherein any number of samples are transported in their respective sampling line using an intermediate pump located in the sampling line.

9. A method as claimed in any one of the preceeding claims performed using apparatus as herein described with reference to the example shown in the accompanying drawing. DATED THIS 22ND DAY OF MAY, 1990 OUTOKUMPU OY By Its Patent Attorneys GRIFFITH HACK CO. Fellows Institute of Patent Attorneys of Australia i 0 04 S1I S0 0 I a t