DPR v17 · Kothakota, Wanaparthy · 23 MT/day RHA → 6,600 MT PS + 9,900 MT PCC per year

How the plant
actually works

From rice husk arriving at the gate to a finished bag of precipitated silica or nano-PCC going onto a truck — every stage, every number, every thing you need to watch.

🌾
Raw Material Intake
›
🔥
Combustion & RHA
›
⚗️
NaOH Leaching
›
💧
PS Precipitation
›
🗜️
Filtration
›
🌪️
Spray Drying
›
♻️
Causticisation & PCC
›
🔬
QC Lab
›
📦
Pack & Dispatch

Process Stages — Raw In to Product Out

01

Raw Material Intake

Everything that enters the plant gate — rice husk, purchased RHA, NaOH lye, CaO, CTAB
Daily Logistics ⌄

What arrives at the gate

  • Rice husk — 20 MT/day. 2–3 tractor trolleys from rice mills within 50 km. ₹5,500/MT. Seasonal ±15% price swing. Each load weighed on floor scale, sampled for moisture.
  • Purchased RHA — 19.4 MT/day. Contract: minimum 90% SiO₂, XRF-verified each delivery. ₹750/MT. 3–4 trucks/day.
  • NaOH 48% lye — 14 MT/day = ~98 MT/week. 5 tanker deliveries per week (20 MT tankers). ₹18,240/MT lye. Highest cost input — invoice every delivery against weighbridge.
  • CaO quicklime — 20.5 MT/day. Daily delivery from Piduguralla, AP (~150 km). ≥85% purity — XRF on every lot before unloading. ₹6,000/MT.
  • CTAB — 0.44 MT/day. Imported surfactant. 4-week buffer stock mandatory. ₹1,80,000/MT. Highest supply risk — track airfreight status weekly.
  • Stearic acid — 0.25 MT/day. Domestic vegetable-based. ₹1,20,000/MT. Buffer: 2 weeks.

Quality checks at gate

  • RHA: XRF SiO₂ % + colour check. White/grey = ≤700°C ✓. Black = unburnt carbon (reject or flag). Pink/brick = ≥900°C cristobalite (hard reject).
  • CaO: Slake test in lab — heat evolution confirms purity. XRF for Ca% and MgO contamination.
  • NaOH: Density measurement on tanker sample = 48% lye confirmation. Titration if density off.
  • Rice husk: Grab sample → moisture meter. >15% moisture = docked price or return.
  • CTAB: COA from supplier mandatory. First use: BET measurement on PS batch to verify activity.
⚠️
Reject black RHA immediately — unburnt carbon contaminates SiO₂ purity and destroys BET surface area. Never blend into a leach batch to "clear" a delivery.

Daily raw material cost at 100% utilisation

NaOH 48% lye (14 MT × ₹18,240)₹2,55,360/day
Rice husk (20 MT × ₹5,500)₹1,10,000/day
CaO quicklime (20.5 MT × ₹6,000)₹1,23,000/day
CTAB (0.44 MT × ₹1,80,000)₹79,200/day
Purchased RHA (19.4 MT × ₹750)₹14,550/day
Total daily input cost≈ ₹7,35,000/day
02

Rice Husk Combustion + Heat Recovery

20 MT/day burns at ≤700°C — generates heat (199.3 GJ/day), bonus RHA (3.6 MT/day) and CO₂ (25.05 MT/day) for free
Critical Control ⌄

What happens

  • Rice husk fed continuously into the Thermax/Raj International furnace at ~0.83 MT/hr (1 MT/hr nameplate)
  • Temperature controlled at ≤700°C. Above this, amorphous SiO₂ converts to crystalline cristobalite — completely unusable and a lung hazard.
  • CEMS (Continuous Emission Monitoring System) measures furnace temp 24×7. Auto-shutoff triggers at 720°C.
  • Combustion gases (CO₂-rich flue gas) piped to precipitation section — zero CO₂ purchase cost ever.
  • Ash collected at furnace base = Bonus RHA: 3.6 MT/day @ zero cost (18% of rice husk mass)
🚨
CEMS calibration is a regulatory requirement (TSPCB CTO condition). If CEMS fails, you legally must shut down the furnace. Keep calibration gas cylinders in stock. Never bypass the 720°C shutoff.

Heat Recovery via THU (Thermal Heating Unit)

  • Hot combustion gases pass through a Forbes Marshall/Thermax THU — Therminol 55 hot oil at 180–220°C, atmospheric pressure. NOT a boiler. No IBR registration required.
  • Hot oil circulates to all heat-using equipment: leach reactors, evaporator, spray dryer preheater
  • Gross thermal available: 199.3 GJ/day at 82% boiler efficiency
  • Process heat needed with MVR: 178.1 GJ/day — leaves 21 GJ/day surplus for Phase 2 (needs second furnace)
  • Without MVR: process needs 224.9 GJ/day → 25.6 GJ/day deficit → plant cannot run at design rate. MVR is mandatory.
Energy balance (v17 — 20 TPD PS, 23 MT/day RHA, with MVR): Gross thermal (20 MT RH × 199.3 GJ/20MT): 199.3 GJ/day Evaporation (with MVR, 65% saving): 89.5 GJ/day NaOH leaching: 65.3 GJ/day Spray drying: 23.1 GJ/day ───────────────────────────────────────────────────── Total process heat: 178.1 GJ/day SURPLUS → Phase 2 (needs 2nd furnace): 21.2 GJ/day

Outputs from Stage 2

Bonus RHA (free, 92% SiO₂)3.600 MT/day
CO₂ for precipitation (internal use)14.2 MT/day
CO₂ surplus (BCR credit upside)10.85 MT/day
Thermal surplus (after MVR process heat)21.2 GJ/day
Flue gas to precipitationPiped continuously
🔧 Thermax furnace 20 TPD · ₹65L 🔧 THU 3.5 MMkcal/hr · ₹48L 🔧 CEMS + auto-shutoff system 🔧 Ash collection + conveyor 🔧 MVR 2-effect evaporator · ₹74L
03

NaOH Leaching — SiO₂ Dissolution

Total 23 MT/day RHA dissolved in hot NaOH solution → sodium silicate (Na₂SiO₃) liquid
Core Reaction ⌄

The reaction

SiO₂ + 2NaOH → Na₂SiO₃ + H₂O Per kg SiO₂: NaOH needed: 1.331 kg Na₂SiO₃ produced: 2.031 kg H₂O produced: 0.300 kg v17 inputs (daily): Total RHA: 23 MT/day (19.4 purchased + 3.6 bonus) SiO₂ available: 21.16 MT/day (× 92%) SiO₂ extracted: 18.62 MT/day (× 88% eff.) NaOH consumed: 24.79 MT/day (gross)
💡
88% extraction efficiency is assumed — this MUST be validated in the lab before engineering freeze. Every 1% drop = 0.122 MT/day less silicate → 0.132 MT/day less PS. Lab validation is Priority 1 pre-commissioning activity.

Operating conditions

  • NaOH concentration: 10% w/v solution
  • Temperature: 90°C (via THU hot oil jacket)
  • Residence time: 2 hours per batch
  • Reactors: 3 × 10 KL PP-lined SS304 reactors (Hydro Air Engineers, Hyderabad). One fills, one reacts, one discharges — continuous production.
  • Agitation: Variable speed agitator, 60–80 rpm
  • pH of silicate solution: 11–13 (strongly alkaline — PPE mandatory)
  • Residue (desilicated): ~3.73 MT/day — filtered off and sold to brick kilns at ₹900/MT = ₹11.07L/yr credit
⚠️
NaOH is the #1 OPEX item. Recovery rate (82% in causticisation) must be tracked DAILY — even a 3% drop in recovery adds ₹2.16L/day cost at v17 scale. Causticisation loop efficiency is the plant's biggest controllable lever.

Mass balance at Stage 3 exit

Na₂SiO₃ solution leaving reactors~37.8 MT/day (as solution)
Desilicated residue to filter press~3.73 MT/day → brick kilns
NaOH consumed (gross, before recovery)~24.8 MT/day
NaOH fresh makeup (after 82% causticisation recovery)6.7 MT/day = 14 MT/day as 48% lye
04

Precipitated Silica (PS) Precipitation

Silicate solution + CO₂ from combustion → SiO₂ precipitates out. pH and temperature control determines product grade.
Product Defining ⌄

The reaction

Na₂SiO₃ + CO₂ + H₂O → SiO₂↓ + Na₂CO₃ Per MT Na₂SiO₃: CO₂ needed: 0.361 MT SiO₂ precipitated: 0.492 MT Na₂CO₃ produced: 0.868 MT v17 daily: CO₂ used: 14.2 MT/day (internal, 5% excess) CO₂ at 5% excess: ×1.05 for pH endpoint PS precipitated: 18.62 MT/day SiO₂ → 20 MT/day finished PS Na₂CO₃ produced: 31.78 MT/day → causticiser CO₂ source: furnace flue gas — zero purchase cost
💡
CO₂ is fed at 5% excess over stoichiometric to ensure complete precipitation and accurate pH endpoint control. Too little → incomplete precipitation. Too much → pH drops too low, product re-dissolves. Bubble reactor with pH feedback controller.

Grade control — what you make depends on pH

  • Standard PS (rubber, animal feed): Final pH 6–9, T 70°C. BET 140–165 m²/g. D50 ≤20 µm. No surface treatment. Export ₹42/kg FOB.
  • HDS (High Dispersibility Silica) for green tyres: pH 6–9, T 50°C (lower = smaller particle). BET ≥165 m²/g. CTAB added post-precipitation. CIPD ≥80%. Export ₹72–84/kg FOB. Year 2+.
  • Dental/Food E551: pH 5.5–8.5, stringent Pb <1ppm, D50 ≤12 µm. Requires FSSAI central licence (Year 3). Export ₹144–152/kg.
  • pH monitoring: Online pH meter + manual check every 30 min. Critical — shift supervisor must verify each batch endpoint.
⚠️
Year 1: Only standard PS (₹42/kg export). DO NOT attempt HDS in Year 1 — CTAB process needs 3–4 months of operator calibration. Ship standard PS to SE Asia buyers while qualifying HDS in parallel.
05

Filtration — Separating PS from Liquor

PS slurry pressed → PS cake (to dryer) + Na₂CO₃ filtrate (to causticisation for NaOH recovery)
Separation ⌄

Equipment & operation

  • 2 × filter presses, 1200mm PP plates (Star/Hydro Press Gujarat). One pressing while one discharges — no downtime.
  • PS slurry pumped at 3–5 bar into plates. Filter press time: 60–90 min per batch depending on cake thickness.
  • Wash step: After pressing, de-ionised water washed through cake 2–3 times to remove residual Na₂CO₃. Critical for food grade (low Na content target).
  • Cake moisture: 60–70% water after pressing. Spray dryer brings this to <5%.
  • Residue cake from Stage 3 leaching also pressed here before brick kiln disposal.
💡
Filter cloth condition is the most maintenance-intensive item in the plant. Inspect cloths after every 20 cycles. Clogged cloth = longer press time = production bottleneck. Keep 2 spare set of cloths always in stock.

Two output streams

  • PS cake (60–70% moisture): Goes directly to spray dryers. Moisture content affects dryer energy and throughput — track daily.
  • Na₂CO₃ filtrate: 31.78 MT/day Na₂CO₃ in solution → this is the input to causticisation (Stage 7). Contains recoverable NaOH value. Never discard.
  • Wash water: Collected in ZLD circuit — recovered and recycled. Never to drain.
PS cake to dryer (v17)~50 MT/day (wet)
Na₂CO₃ filtrate to causticiser31.78 MT/day
Wash water → ZLD recoveryRecirculated
06

Spray Drying — Final PS Product

Wet PS cake → dry white powder. Two spray dryers, continuous. Surface treatment (CTAB for HDS, stearic for coated grades) added here.
Product Out ⌄

Equipment & operation

  • 2 × spray dryers — Raj Process Equipments, Pune. SS304 body, SS316L contact parts. ₹121L. Each handles ~16 MT wet cake/day.
  • Atomisation: Rotary disc atomiser (better for silica slurry — avoids nozzle clogging). Inlet temp: 180–220°C (from THU hot oil). Outlet: 60–80°C.
  • Dry PS powder falls into conical bottom, conveyed to packaging or surface treatment vessel.
  • HDS surface treatment: CTAB solution sprayed into the dryer outlet stream or in a separate paddle mixer. Temperature-sensitive — do not exceed 100°C during CTAB treatment.
  • Product moisture spec: <5% for standard, <3% for dental/HDS.
💡
Rotary atomiser wear is the main maintenance item. Check disc rpm and bearing temp every shift. A worn disc produces wider particle size distribution — directly affects BET and customer complaints.

PS output per grade (v17 — from Day 1)

Standard PS (Year 1 — 100%)20 MT/day · 6,600 MT/yr · 833 kg/hr
HDS PS (Year 2+ — partial)Up to 30–40% of output
Dental/Food E551 (Year 3+)5–10% initially
Bag size: 25 kg multi-wall kraft800 bags/day at 100% util
Bulk bags (500 kg/1 MT FIBC)For export FCL

Revenue at exit gate (v17 Y1)

6,600 MT/yr × ₹42/kg export FOB₹27.72 Cr/yr gross PS
At 60% Y1 utilisation~₹16.63 Cr PS revenue
07

Causticisation — NaOH Recovery + Nano-PCC Production

This one stage does two jobs simultaneously: recovers 82% of NaOH (back to leaching) AND produces nano-PCC as an obligatory co-product
Circular Core ⌄

The reaction — two products from one step

Na₂CO₃ + Ca(OH)₂ → 2NaOH + CaCO₃↓ Per kg Na₂CO₃: Ca(OH)₂ needed: 0.699 kg NaOH recovered: 0.755 kg ← back to leach CaCO₃ (nano-PCC): 0.944 kg ← sold as product v17 daily (31.78 MT Na₂CO₃): Ca(OH)₂ needed: 22.21 MT/day CaO to slake: 20.5 MT/day (at 85% purity) NaOH recovered: 23.99 MT/day (82% of gross circuit) Nano-PCC produced: 30 MT/day = 9,900 MT/yr · 1,250 kg/hr
💡
PCC is NOT optional. The Na₂CO₃ must be converted back to NaOH — CaCO₃ precipitates out as a side effect. Skipping PCC recovery means discarding ₹4+ Cr/yr revenue and creating a solid waste problem. PCC is obligatory.

CaO slaking — on-site mandatory

  • CaO slaker on-site: CaO + H₂O → Ca(OH)₂. Exothermic (−63.7 kJ/mol) — slaker design handles heat. Never buy pre-slaked Ca(OH)₂ — price premium of 40–60% kills economics.
  • Draft-tube causticiser: Proprietary design — higher Ca(OH)₂ contact, smaller particle size PCC, better NaOH conversion. ₹27L equipment. More than paid back in PCC quality.
  • NaOH recovery rate: 82% — this is the critical efficiency metric. Lab-validate before commissioning. Target 84–86% post-optimization.
  • 2-stage PCC hydrocyclone (Krebs Engineers, Vadodara, D4+D6): classifies PCC by particle size — coarse (2 µm, bulk coatings) vs fine (0.7 µm, sealant grade).

PCC grades and revenue (v17 — 9,900 MT/yr)

Bulk PCC (coatings/paints) — 2 µm4,500 MT/yr × ₹10/kg = ₹4.5 Cr/yr
Sealant PCC (stearic coated) — 0.7 µm3,000 MT/yr × ₹26/kg = ₹7.8 Cr/yr
Plastics/PP grade — 0.5 µm (Year 2+)2,400 MT/yr × ₹42/kg = ₹10.1 Cr/yr
NaOH saved vs buying fresh23.99 MT/day × ₹18,240 = ₹4.38L/day = ₹144 Cr/yr avoided cost
08

QC Laboratory

Every batch gets a Certificate of Analysis before it leaves. This is what keeps export customers and justifies ₹42–152/kg pricing.
Quality Gate ⌄

Test equipment (₹32L)

  • BET surface area analyser (N₂ adsorption): Target 140–200 m²/g for standard PS. HDS needs ≥175 m²/g CTAB surface area. Most critical spec for tyre customers.
  • Laser particle size (PSD): D50 ≤20 µm standard, ≤12 µm dental. D50 is also PCC grade classifier.
  • XRF elemental: SiO₂ purity, Fe, Al, Na, Ca, Pb. Dental grade: Pb <1 ppm mandatory.
  • pH meter, moisture analyser, oil absorption: routine per batch.
  • CTAB absorption test: For HDS — measures available surface for silane coupling in tyre rubber. Spec: ≥175 mg/g.

Testing schedule

  • Every batch: pH, moisture, bulk density, visual colour
  • Every shift: PSD (D50, D90), SiO₂ purity (XRF)
  • Every 24 hours: BET surface area, oil absorption
  • Every week: Full elemental (Pb, Fe, Na, Ca, Al), CTAB for HDS lots
  • Every export lot: Full COA printed, signed by QC Engineer, retained for 5 years
  • Customer samples: 500g to 1kg samples dispatched via courier before FCL shipment
⚠️
The QC lab is your export licence. No COA = no payment from overseas customers. Hire QC Engineers with BET experience — not just chemistry graduates. Lab setup must be done and calibrated 2 months before first commercial batch.
09

Packaging, Warehousing & Dispatch

25 kg bags, FIBC bulk bags, container loading for export. 1–2 trucks outbound daily at 60% utilisation.
Revenue Out ⌄

Packaging options

  • 25 kg multi-wall kraft bags: Standard domestic and export. ~800 bags/day (v17, 100% util). Semi-automatic packing line.
  • 500 kg / 1 MT FIBC jumbo bags: Preferred for export FCL — fewer bags, lower labour, better container fill. Target: 90% of export in FIBCs.
  • Labelling: Grade, lot number, COA QR code, Fluxara logo, FSSAI number (once certified), REACH reference (once registered). Export labels bilingual.
  • Warehouse: 400 MT covered storage capacity. FIFO strictly. Humidity <60% — PS absorbs moisture. Check monthly with hygrometer.

Export logistics

  • Port options: Krishnapatnam (320 km, preferred — closest) or Chennai (380 km). Road by reefer-capable truck. ~₹45,000–60,000/FCL truck.
  • FCL frequency (v17, Y1 60%): ~5 FCL containers/month at Y1 60%. At 100% steady state: 8–10 FCL/month.
  • PCC dispatch: Domestic customers — smaller loads, direct factory trucks or courier depending on volume.
  • Documents per export shipment: Invoice, packing list, COA, SDS, MSDS, IEC declaration, fumigation certificate. Freight forwarder manages customs.
  • Payment terms: Target LC at sight (letters of credit) for new customers. Advance 30% for established.

Daily output summary (v17 at 60% Y1)

PS produced per day (60% util)12 MT/day = 480 × 25kg bags · 500 kg/hr
PCC produced per day (60% util)18 MT/day · 750 kg/hr
Desilicated residue to brick kilns2.24 MT/day → ₹2,016/day
Outbound trucks per day (PS)2–3 trucks (10–15 MT loads)

Workforce — 28 People, ₹1.40 Cr/yr, What You're Actually Managing

You are running a 3-shift, 24×7 continuous chemical plant. The workforce is lean — 28 people covering all functions. This is not a factory where you visit occasionally. The Plant Manager is your eyes, and every shift handover is a critical event.

28
Total headcount
3
Operating shifts/day
₹1.40Cr
Annual payroll
₹5.0L
Avg CTC (all staff)
24×7
Continuous operation
Plant Manager
×1
₹18–24 L CTC · Live on-site
  • Morning: reads all 3 shift logs, checks CEMS data, reviews production vs target
  • Manages every vendor relationship — NaOH supplier, CaO, CTAB, freight
  • Signs off COAs, authorises dispatch of every lot
  • Owns the P&L of daily OPEX — tracks NaOH recovery rate weekly
  • Your direct report. Weekly call minimum. Monthly board report.
  • Must have 15+ yr chemical plant experience. Non-negotiable.
Process Engineers
×2
₹8–12 L CTC · Day shift + on-call
  • Own the process parameters — leach pH, precipitation endpoint, causticisation efficiency
  • Weekly causticisation lab audit (NaOH recovery %) — escalate if below 80%
  • Approve grade changes (switching standard → HDS production run)
  • Process deviation reports — every batch that fails spec goes through them
  • Support RFQ technical responses to customers
Shift Supervisors
×3 (one per shift)
₹5–7 L CTC · Rotating 8-hr shifts
  • Shift handover: reads prior shift log, walks the plant, signs handover register
  • Controls furnace temperature — monitors CEMS every 30 min
  • Authorises each new leach batch start and precipitation pH target
  • Manages 3 operators — breaks, task allocation, safety
  • Any equipment fault: calls Plant Manager immediately
  • Shift log is a legal document — completed without gaps
Process Operators
×9 (3 per shift)
₹2.4–3.6 L CTC · Rotating
  • Operator 1: Furnace + THU + ash collection
  • Operator 2: Leach reactors + filter press + pH monitoring
  • Operator 3: Spray dryer + packing + causticiser
  • Sample every batch from reactor discharge — pH, temp, visual
  • Log every reading in the shift register
  • PPE: always — NaOH is caustic, CO₂ in confined space, silica dust
QC / Lab Engineers
×2
₹5–8 L CTC · Shift 1 + Shift 2
  • Run BET, PSD, XRF on every lot before release
  • Generate and sign COAs — no lot leaves without one
  • Maintain calibration records for all lab instruments
  • Prepare customer samples, coordinate courier dispatch
  • Report weekly: batch pass rate, grade distribution, reject reasons
Maintenance
×1
₹3.6–4.8 L CTC · Day + on-call
  • Daily: filter press cloth inspection, spray dryer atomiser check, pump seals
  • Weekly: belt/chain lubrication, valve actuator checks, PLC I/O scan
  • Monthly: MVR evaporator tube inspection, THU expansion vessel level
  • Maintains spare parts inventory — minimum 30-day buffer on critical items
  • Critical spares always on-site: filter cloths, pump impellers, thermocouple probes, pH electrodes
Admin / Accounts
×2
₹2.4–3.6 L CTC · Office hours
  • Purchase orders for all raw materials — NaOH purchase order is a daily event
  • Weighbridge records, GRN, supplier invoices vs COA match
  • GST filing monthly, TDS quarterly, payroll
  • Bank correspondence — loan drawdown schedule, DS payment calendar
  • Export documentation — invoices, packing lists, DGFT filings
Helpers + Security + Driver
×6
₹1.8–2.4 L CTC
  • Helpers ×3: Bag loading, material movement, cleaning — critical for dust control
  • Security ×2: Gate entry/exit log (raw material trucks, finished goods), visitor register, night rounds
  • Driver ×1: RHA procurement runs, sample courier, vendor visits, bank/admin runs for Plant Manager

A Day in the Plant — What You're Dealing With

06:00
Night → Morning shift handover.OPS Shift supervisor walks the plant, reads night log. CEMS printout reviewed — any temp spikes overnight? NaOH tanker that arrived at 2am — weighed and documented correctly?
07:00
Plant Manager morning review.MGMT Reviews all 3 shift logs. Checks: yesterday's production MT vs target, NaOH used vs theoretical (recovery %). Any equipment downtime? Calls pending with vendors?
07:30
Raw material deliveries begin.LOGISTICS CaO truck from Piduguralla arrives first. Weighbridge + XRF slake test. Rice husk tractors start coming in — 2–3 loads before noon. Security logs every truck, time-stamped.
08:00
QC lab opens.QC Tests last night's PS batches — BET, PSD. If a batch fails (BET too low, moisture high), hold it. Do not pack until re-tested. COAs printed for yesterday's released lots.
09:00
NaOH tanker.CRITICAL 20 MT NaOH 48% lye tanker arrives (3×/week). Density check on sample. Invoice verified against purchase order. Discharged to storage tanks. Track: cumulative NaOH received vs consumed this month — any gap = recovery problem or leak.
10:00
First PS batch ready from night shift.PRODUCTION Spray dryer discharge to packing line. Packing operators bag, weigh, label. Supervisor spot-checks 3 bags per pallet. Pallet tagged with lot number and hold/release status.
11:00
Maintenance walkthrough.MAINT Filter press cloth inspection on the unit that discharged this morning. Spray dryer atomiser rpm check. THU oil level + pressure gauge. Pump seal visual on causticiser feed pump.
13:00
Export truck loading.DISPATCH If today is a shipping day (~3×/week at Y1 60%), FIBC bags loaded onto truck. Security gate exit documented. Driver given shipping docs + COA copies. Export invoice raised.
14:00
Morning → Afternoon shift handover.OPS Same as morning — logged, signed, supervisor walks the plant. CEMS calibration check (required weekly, do it now if due).
15:00
Admin: vendor payments, bank.ADMIN NaOH supplier payment if invoice matches. Purchase orders for next week's CaO and rice husk. GST on last week's dispatches filed by end of week.
17:00
Process Engineer daily check.PROCESS Reviews today's precipitation pH data — any batches that drifted outside spec range? Checks Na₂CO₃ concentration in causticiser feed — if too dilute, recovery will drop. Adjusts tomorrow's operating parameters if needed.
22:00
Night shift begins.OPS Plant runs through the night continuously. Furnace, leach reactors, spray dryers — all operating. Shift supervisor alone manages operations. Plant Manager on-call. CEMS auto-alerts to phone if temp >700°C.
Always
What you're monitoring remotely.REMOTE SCADA dashboard (Ignition): furnace temp, spray dryer inlet/outlet temps, reactor pH and temp, MVR operating pressure, ZLD tank levels. NaOH consumption vs production — the most important daily metric for you personally.

What to Watch — Your Top Operational Risks

🌡️

Furnace temperature exceeds 700°C

Even 30 minutes at 750°C converts amorphous SiO₂ to cristobalite. The entire batch is scrap. CEMS auto-shutoff is your last line of defence — test it weekly. Never disable it "temporarily".

📉

NaOH recovery rate drops below 78%

The causticisation loop is the plant's financial core. At 82% recovery you need 4.375 MT/day fresh NaOH. At 75%, you need 6.1 MT/day — ₹1.14L/day extra cost. Check weekly. Investigate immediately if it drops.

📦

CTAB stock below 2-week buffer

CTAB is imported — 4–6 week lead time. If you run out, HDS production stops. You can still make standard PS, but at ₹42 vs ₹72/kg. Track airfreight status personally when stock drops below 30 days.

💧

MVR evaporator performance degradation

If MVR efficiency drops, process heat deficit opens up. Plant throughput must be reduced to match available heat. Monitor MVR steam economy ratio (kg water evaporated per kg steam) weekly. Target ≥8.

🧪

PS batch failing BET spec

Low BET = low surface area = customer rejection risk. Most common causes: pH not reaching endpoint, CTAB dose incorrect, spray dryer temp too high. Each held batch is cash tied up in stock.

🚚

RHA quality inconsistency

SiO₂ purity below 90% or high carbon content throws off the mass balance. Your production falls without you knowing why. XRF every delivery — non-negotiable. Black ash = reject.

⚡

DISCOM power quality / outages

At 454 kW operating load, a 30-minute outage mid-precipitation can ruin a batch (pH endpoint missed). Verify UPS coverage for SCADA, CEMS, and pH controllers. Plan generator backup for critical instruments.

🔬

Lab instrument downtime

If the BET analyser goes down, you cannot release any lot. Production backs up in 48 hours. Service contract with the BET supplier is mandatory. Turnaround for a service visit in Telangana: 3–5 days. Keep a backup pH reference standard and calibration solutions on-site.