DILUTE Process

To access this process:

See this process in the Command Table.

Introduction

Allows the extension of drillhole seam intersection data to allow for dilution above and below seams.

The input drillhole data file must contain *FROM and *TO fields, which define the ranges of a particular seam or horizon intersection with a unique value of the field *SEAMID. This type of file may be an assay file, or a 'desurveyed' file in standard sample format, or may be constructed by the user. The file must be sorted in order of the drillhole identifier (*BHID) and *FROM fields. 

Dilution is carried out by subtracting the distance specified by parameter @DILUP from the *FROM of the top of each seam specified by *SEAMID, and by adding the distance @DILDOWN to the *TO of the seam. These parameters may be either positive or negative. If positive, then each seam is expanded; this corresponds to mining dilution. If negative, then each seam is contracted; this corresponds to leaving material in the floor and roof.

If the dilution envelopes of two different seams intersect, they are adjusted to prevent overlap. If the dilution envelopes of two intersections, which are identified as part of the same seam, meet, the two intersections are combined into one. If the dilution parameters are negative then seams will be removed if the total thickness becomes zero or negative. If a seam top should be extended upwards to give a negative *FROM, the value is set to zero.

A cut-off intersection thickness may be specified (after dilution) by use of the optional parameter @THINNEST.

These calculations are performed on downhole distances, and therefore do not take into account the direction of the hole. DILUTE is thus only suitable for drillholes with essentially the same orientation (for example, vertical).

Note: where dilution envelopes of adjacent seams intersect, each is reduced by an appropriate factor to remove the overlap. This factor is computed to maintain a ratio of DILDOWN:DILUP between the thicknesses assigned to the upper and lower of the two seams respectively.

Input Files

Name

Description

I/O Status

Required

Type

IN

Input file. Must contain at least fields for BHID, FROM, TO and SEAMID.

Input

Yes

Undefined

Output Files

Name

I/O Status

Required

Type

Description

OUT

Output

Yes

Undefined

Output file.

Fields

Name

Description

Source

Required

Type

Default

BHID

Borehole identifier. May be numeric or alpha.

IN

Yes

Any

BHID

FROM

Downhole FROM distance (top of intersection).

IN

Yes

Numeric

FROM

TO

Downhole TO distance (base of intersection).

IN

Yes

Numeric

TO

SEAMID

Identification for intersections. Must be numeric or alpha up to a maximum of 4 chars.

IN

Yes

Any

SEAMID

Parameters

Name

Description

Required

Default

Range

Values

DILUP

Dilution distance up from FROM positions.

Yes

Undefined

Undefined

Undefined

DILDOWN

Dilution distance down from TO positions.

Yes

Undefined

Undefined

Undefined

THINNEST

Thinnest acceptable seam. Any thinner intersections are eliminated.

No

Undefined

Undefined

Undefined

Example

This example shows dilution of all seams in file 'SEAMS' by adding 0.3 metres to the top and 0.5 metres to the bottom of each seam.

!DILUTE &IN(SEAMS), &OUT(SEAMS1), *BHID(BHID), *FROM(FROM), *TO(TO), *SEAMID(SEAM), @DILUP=0.3, @DILDOWN= 0.5, @THINNEST= 1

Error and Warning Messages

Message

Description

>>> ERROR nnnn SEAMS IN HOLE AT RECORD rrrrr <<<

There is a limit of 50 seams in each drillhole. Fatal; the process is exited.