Thông tư 06/2011/TT-BTNMT

CIRCULAR

STIPULATING ON QUALITY CONTROL OF RESULTS OF ANALYSING THE MINERAL AND GEOLOGICAL SAMPLES

THE MINISTER OF NATURAL RESOURCES AND ENVIRONMENT

Pursuant to the Law on minerals, Law amending and supplementing a number of articles Law on minerals;

Pursuant to the Government's Decree No. 25/2008/ND-CP dated March 04, 2008, defining the functions, duties, power and organizational structure of the Ministry of Natural Resources and Environment;

Pursuant to the Government's Decree No. 89/2010//ND-CP dated September 18, 2010, amending and supplementing Article 3 of the Government's Decree No. 25/2008/ND-CP dated March 04, 2008 defining the functions, duties, power and organizational structure of the Ministry of Natural Resources and Environment;

At the proposal of the Director of the Vietnam Geology and Mineral Department and Director of the Legal Affair Department,

DECIDES:

Chapter I.

GENERAL PROVISIONS

Article 1. Scope of regulation and subjects of application

1. This Circular stipulates on the quality control, assessment on reliability of results of analyzing geological and mineral samples by quantitative method.

2. This Circular applies to state agencies, laboratories, organizations and individuals conducting tasks of geological basic survey and mineral resource geological basic survey; mineral exploration under the state management of the Ministry of Natural Resources and Environment.

Article 2. Interpretation of terms

1. Basic sample means the sample which has been processed, taken partly as a representative for analyzing at the request of sender. 

2. The saved analysis sample means the remaining sample which has physical characteristics and material components completely same as the basic sample and is saved, preserved in accordance with current regulations.

3. The control sample includes:

a) The standardized sample means the sample which is manufactured from soil, rock or ore being announced by competent agencies, with enclosed certificate.

b) Blank sample means the sample which it has been known that components need be analyzed less than the detecting limitation of method.

c) Duplicate sample means the sample taken from the processed sample and coded to send together with the basic sample by sender, with analysis requirements same as the basic sample. 

d) Repeated sample means the sample which is taken from the saved analysis sample, sent for re-analyzing.

e) The antiparallel sample means the sample which is taken from the saved analysis sample and coded, sent for analyzing by a different analysis method or by a different laboratory.   

Article 3. Requirements on quality control of results analyzing samples

1. Quality control of results analyzing samples must be conduct independently with examination operation which is organized implementation by laboratories.

2. Quality control must be conducted continuously for each sample batch sent for analysis. A basic sample batch must be compulsorily enclosed at least one of types of quality control sample.  Each basic sample batch is not more than 30 samples.

3. For each analysis criterion to define high-level natural resource, it must have 2 to 3 in 6 types of quality control sample specified in Article 2 of this Circular.  

4. Conditions of laboratory (or method) of the comparing analysis must have the reliability higher than or equal to conditions of laboratory (or method) of the basic sample analysis.

5. The antiparallel sample is used in case where there is no appropriate standardized sample.

Chapter II.

SELECTION AND SENDING OF THE QUALITY CONTROL SAMPLE

Article 4. Selection of the quality control sample

1. Quantity of quality control sample is depended on the complicated nature of the analyzed object, ability of the analysis method and quantity of the basic analysis samples.   Total quality control samples is more than or equal to 10% of total basic samples.

2. The quality control of results of analyzing sample is prioritized for areas of which natural resource characteristic is defined at high level.

Article 5. Sending of sample

1. When sending the samples for quality control, all types of samples must be processed up to condition satisfying requirements of analysis according to the existing regulation, technical standards and the processing procedure of geological and mineral samples used for the testing analysis.

2. The quality control sample must be coded to ensure science, avoid mistakes and keep secret for laboratory.

3. The batch of samples sent for the comparing analysis must have the duplicate samples conducted as prescribed in Clause 2 Article 3 of this Circular. 

Chapter III.

ERROR ESTIMATION AND HANDLING OF ANALYSIS RESULTS

Article 6. Estimation of relative errors

1. The formula of calculating relative error is used for calculating pairs of basic samples and duplicate samples (or the identical samples or the antiparallel samples).

Average value

In which:

S is relative error

 X_cb is result of analyzing the basic sample.

X _ks is result of analyzing the duplicate sample or identical samples or the antiparallel samples.

2. To compare the found value of S with the allowed value of standard deviation δp at level of respective content specified in Annex 1. The allowable relative errors, promulgated together with this Circular.  

If |S| ≤ δp : The analysis result is accepted.

If |S| > δp : The analysis result is not accepted.

Article 7. The error estimation of analyzing the standardized samples

Calculation of the accuracy for each analysis criterion is applied to the formula: σ = 0.02

CC is the identified value (content of elements or components of the standardized sample).

To use the Z value calculated under the formula defined in Clause 2 of this Article for error estimation.

2. Calculation of Z value:

_s is the accuracy calculated under the formula.

C_PT: is value of result of analyzing the standardized sample.

3. Estimation of error:

a) If the absolute value of S is less than or equal to 4 (|Z| ≤ 4), the analysis quality is assessed as good and the analysis result has sufficient reliability.

b) If the absolute value of S is more than 4 (|Z| >4), the analysis quality has not yet had sufficient reliability.

Article 8. The error estimation of analyzing the antiparallel samples

1. The estimation of relative errors of analyzing the duplicate sample of the antiparallel sample will comply with Article 6 of this Circular.

a) If the basic analysis result of the antiparallel sample is not accepted, that analysis result will not be used to assess the antiparallel error.

b) If the basic analysis result of the antiparallel sample is accepted, that analysis result will be used to assess the antiparallel error.

2. The error estimation of antiparallel analysis will comply with Article 6 of this Circular.

a) If the analysis result is accepted, the sample analysis quality basically satisfies requirements.

b) If the analysis result is not accepted, the sample analysis quality basically has not yet had sufficient reliability.

Article 9. The error estimation of analyzing the blank samples

The result of analyzing the blank sample is compared to the defined limitation value of method.

1) If the result of analyzing the blank sample is less than the defined limitation value of method, the analysis result basically has sufficient reliability.

2) If the result of analyzing the blank sample is more than or equal to the defined limitation value of method, the analysis result has insufficient reliability.

Article 10. Handling of analysis results

1. To make a statistical table of analysis results as prescribed in form 1, Annex II promulgated together with this Circular.

2. To make error estimation as prescribed in Articles 6, 7, 8 and 9 of this Circular.

3. To handle errors, compare cases happening as prescribed in the Table for handling of the analysis results as follows:

Table 1: Handling of analysis results

a) Case 1: The analysis result has sufficient reliability for use.

b) Case 2: It is able to have errors systemically; the sending-sample party must notify in writing for laboratory, make minutes to annul all the analyzed results.

b) Case 3: It is able to have errors randomly; the sending-sample party must notify in writing for laboratory, two parties together consider finding out the reason.

- If reason of error is caused by the sample sender,  a minutes of annulling all the analysis result must be made, the sample sender must re-make a new batch of samples as prescribed in Clause 2 Article 3 of this Circular for sending it for  analyzing.

- If reason of error is caused by laboratory, the minutes of annulling all the analysis result must be made; the laboratory shall re-analyze the sent batch of samples.

d) Case 4: The analysis result has not yet sufficient reliability for use, the sending-sample party notify in writing for laboratory, make a minutes to annul all the analyzed result; stop the sending of samples to laboratory, report to management agencies for consideration and settlement.

Chapter IV.

RESPONSIBILITIES OF ORGANIZATIONS AND INDIVIDUALS SENDING SAMPLES, AND LABORATORIES

Article 11. Responsibilities of organizations and individuals sending samples

1. The supervision of sample analysis quality is compulsory requirement when conduct tasks of basic geological survey and basic geological survey of geology and mineral resources; mineral exploration.

2. In report of implementation result must sum up fully figures of quality control, reliability assessment of analysis results used in report. Basic content of report on quality comply with Annex 2 promulgated together with this Circular.

3. Within 30 days after receiving the analysis result, the party sending sample must handle, assess the quality of analyzing sample for quality control. If one of types of quality control sample fails to satisfy requirement, the party sending sample must notify in writing for laboratory so that two parties consider, find out reason of errors and unify measure for resolving.  The minutes shall be made according to Annex 2 promulgated together with this Circular.  If reason of errors is caused by the party sending sample (such as mistake in taking sample, coding wrong sample, select unsuitable sample…), the party sending sample will have to pay expenses when re-analyzing. 

4.  The minutes are stored in initial dossier of documents.

Article 12. Responsibilities of laboratory

1. To facilitate for the party sending sample to take the stored analysis sample so as to send duplicate sample, repeated sample, antiparallel sample.

2. When receive comments of the party sending sample, laboratory must reply in writing about the sample analysis quality within 10 days.

3. If reason of error is caused by laboratory, when re-analyzing, expenses will be paid by laboratory.

Chapter V.

PROVISIONS OF IMPLEMENTATION

Article 13. Funding for implementation of the quality control

In project of geological basic survey and geological basic survey of mineral resource; mineral exploration, it is required to design full number of samples for quality control. Funding for implementation of the quality control is made estimation during elaborating project.

Article 14. Effect

1. This Circular takes effect on March 15, 2011. To annul the Decision No. 69 QD-DC/KT dated May 29, 1996, of the Director of Vietnam Geology Department, promulgating regulation on geological examination of element content in the geological sample.

2. The Director of Geology and Minerals Department, units under the Ministry of Natural Resources and Environment, organizations and individuals conduct projects, and laboratories shall implement this Circular.

ANNEX I

THE ALLOWABLE RELATIVE ERRORS
(Enclosed with the Circular No. 06/2011/TT-BTNMT dated January 29, 2011 of the Minister of Natural Resources and Environment)

THE ALLOWABLE RELATIVE STANDARD DIFFERENCE % TABLE 1

Note:

Au₁: Fine disseminated-gold sample, size of < 0.1mm;="">

Au₂: Average disseminated-gold sample, size of < 0.6mm;="">

Au₃: Unrefined disseminated-gold sample, size of > 0.6mm

TABLE 2

TABLE 3

TABLE 4

TABLE 5

TABLE 6

ANNEX II

(Enclosed with the Circular No. 06/2011/TT-BTNMT dated January 29, 2011 of the Minister of Natural Resources and Environment)

REPORT ON THE QUALITY CONTROL OF ANALYZING SAMPLES

The report must sum up full various information, which includes the process of implementation, comments, assessment of reliability of analysis results, the making of statistical table, summing up of analysis results. The detail reports are presented according to the following forms:

FORM 1

The statistical table of sending samples for quality control of whole scheme

- Division of basic analysis.

- Requirements of analysis

- Total basic samples of whole project.

- Number of times sending samples for analysis.

- Total samples for quality control.

(The presentation of results of quality control samples of whole scheme may use specialized software programs for presentation)

FORM 2

The statistical table of results of analyzing the duplicated sample (or antiparallel samples) of whole scheme

- Criteria of analysis:

- Division of basic analysis.

- Division of antiparallel analysis (if any).

- Method of basic analysis.

- Method of antiparallel analysis (if any).

- Total basic samples of whole project.

- Number of times sending samples for analysis.

- Total samples for quality control.

FORM 3

The statistical table of results of analyzing the standardized samples of whole scheme

- Criteria of analysis:

- Division of basic analysis.

- Method of basic analysis.

- Number of times sending for analyzing the standardized sample.

- The standardized content

FORM 4. Minutes

Minutes of

Handling of the analysis result of quality control samples which fail to satisfy requirements

1. Time: :…….o’clock ………. date……… month………. year…………

- Location at: …………………………………………………………………

- Content: …………………………………………………………………

2. Participants:

- Representative of unit sending sample ………………… ………………………………..

- Representative of laboratory:…………….

3. Content of discussion:

-…………………………………..(3)………………………………………………..

4. The result of handling

-………………………………..(4)…………………………………………………

.………………………………………………………………………………………..

Receivers:

Note:

(1): Inscribing location where the minutes is made

(2) Inscribing the content which is discussed, considered about the analysis results failing to be accepted by two parties (code number of sample, number of analysis slips, analysis result).

(3) Unifying in finding reason of causing error

(4) Inscribing opinion of handling. To annul the analysis result, or re-analyze, analyze additionally.