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RQD / Core Recovery Calculator

Review interval-by-interval core length, recovered length, RQD, core recovery, and core loss in one place.

It supports both from/to interval entry and direct core piece lengths, with units and decimal places controlled from Settings.

Samples

Sound core interval

Input Run length 1.00 m, core pieces 32 cm / 28 cm / 22 cm / 18 cm

Output RQD 100.0%, core recovery 100.0%, quality class Excellent

Fractured interval

Input Run length 1.00 m, core pieces 18 cm / 14 cm / 9 cm / 8 cm / 7 cm / 6 cm / 5 cm / 4 cm

Output RQD 32.0%, core recovery 71.0%, quality class Poor, fracture zone flagged

Low-recovery long run

Input Run length 10 ft, core pieces 18 in / 12 in / 8 in

Output RQD 31.7%, core recovery 31.7%, loss flag shown

Түгээмэл асуултууд

RQD гэж юу вэ?

RQD нь Rock Quality Designation гэсэн үгийн товчлол бөгөөд cutoff-оос урт цөмийн хэсгүүдийн нийлбэрийг run length-д хуваасан хэмжээ юм.

From/to гүн ба run length-ийг зэрэг оруулж болох уу?

Тийм. Хэрэв хоёуланг нь оруулбал run length ба from/to-ийн зөрүү хангалттай таарч байгаа эсэхийг багаж сануулна.

Core piece-ийн жагсаалтад нэгж холиж болох уу?

Тийм. Нэгж тэмдэглэгээтэй утгуудыг хольж болно. Нэгжгүй утгыг одоогийн хэсгийн нэгжээр тайлбарлана.

Аравтын таслалыг дэмжих үү?

Тийм. 1,25 гэх мэт оруулгыг зөвшөөрнө.

RQD 100%-аас их байж болох уу?

Ерөнхийдөө үгүй. Хэрэв тийм бол нэгжийн алдаа эсвэл давхардсан оролтыг шалга.

Glossary

RQD

The sum of core piece lengths longer than the cutoff, divided by the run length.

Core recovery

The total recovered core length divided by the run length.

Run length

The total length of the drill interval.

Core piece length

The length of each recovered core fragment.

Cutoff length

The minimum piece length counted toward RQD.

Formulas

  • map[Text:recovery = recovered_length / run_length × 100 text:recovery = recovered_length / run_length × 100]
  • map[Text:rqd = sum(piece_length >= cutoff_length) / run_length × 100 text:rqd = sum(piece_length >= cutoff_length) / run_length × 100]
  • map[Text:core_loss = max(run_length - recovered_length, 0) text:core_loss = max(run_length - recovered_length, 0)]
  • map[Text:quality_class = RQD-based classification text:quality_class = RQD-based classification]
  • map[Text:fracture_flag = RQD < threshold or quality class is Poor/Very poor text:fracture_flag = RQD < threshold or quality class is Poor/Very poor]
  • map[Text:loss_flag = core recovery < threshold text:loss_flag = core recovery < threshold]

Notes

  • This tool is a screening aid, not a replacement for geologic interpretation or mine planning.
  • If you enter both from/to depths and run length, always check unit consistency.
  • Tune the cutoff length and thresholds to your site standards.
  • If a result exceeds 100%, suspect a unit mistake or duplicated input.

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